OPINION
Facts and Procedural History
Appellant, Donegal Mutual Insurance Company (“Donegal”) asks this court to determine whether multiple shootings perpetrated by Richard Baumhammers (“Baumhammers”), an adult, resulting in the death of five individuals and serious bodily injury of a sixth, qualifies as an “accident” pursuant to Donegal’s insurance policy, requiring Donegal to provide coverage to Andrejs and Inese Baumhammers, the parents of Richard Baumhammers. Donegal additionally asks this court to determine whether the alleged negligence of Andrejs and Inese Baumhammers and the subsequent shootings by their son constitute a single “occurrence” under Donegal’s insurance policy or whether each shooting of the victims constituted a separate occurrence. We affirm the Superior Court’s decision that an “accident” happened, but reverse the Superior Court’s finding that the instant facts support a finding of multiple occurrences.
On April 28, 2000, Baumhammers left his home and shot and killed his neighbor, Anita Gordon, at her home which he then set on fire. He then drove to Scott Township where he killed Anil Thakur and seriously wounded Sandip Patel, after which he drove to Robinson Township and shot and killed Ji-Ye Sun and Thao Pak Pam. Finally, Baumhammers drove to Center Township where he shot and killed Garry Lee. The entire series of events occurred within a two hour time period. On May 9, 2001, Baumhammers was convicted of first degree murder with respect to the five victims who had died, and aggravated assault and attempted homicide for the shooting of Patel.
Patel and the personal representatives of the estates of the deceased victims (“Plaintiffs”) filed complaints against Baumhammers and his parents in the Court of Common Pleas of Allegheny County, consolidated at GD 00-10558. The complaints allege the following omissions by Parents: (1) failure to procure adequate mental health treatment for Baumhammers, (2) failure to take Baum-*289hammers’ handgun away from him, and (3) failure to notify the appropriate authorities of the fact that Baumhammers possessed a handgun. Donegal v. Baumhammers, GD 01-5671, GD 00-18199, slip op. at 6 (Ct. Com. Pleas of Allegheny Cty. Aug 7, 2002) (“Trial Court op.”).1
Andrejs and Inese Baumhammers (“Parents”) are insured under a homeowners policy issued by Donegal. The policy covers Parents as well as any relative residing in the household. Baumham-mers resided in his parents’ home at the time of the shooting incidents. The Done-gal insurance policy provides coverage for claims brought against an insured for damages resulting from bodily injury caused by an “occurrence.” R. 92. The policy describes its coverage limits for bodily injury as follows:
Limit of Liability. Our total liability ... for all damages resulting from any one “occurrence” will not be more than the limit of liability ... as shown in the Declarations. This limit is the same regardless of the number of “insureds,” claims made or persons injured. All “bodily injury” and “property damage” resulting from any one accident or from continuous or repeated exposure to substantially the same general harmful conditions shall be considered to be the result of one “occurrence.”
R. 97,118.
The limit of liability for personal injury under the Donegal policy is $300,000 per “occurrence.” R. 118. The policy defines an “occurrence” as an “accident, including continuous or repeated exposure to substantially the same general harmful conditions, which results, during the policy period in ... [b]odily injury or [property damage.” R. 81. The term “accident” is not defined in the policy. Pursuant to the policy, Donegal agreed to “[pjrovide a defense at our expense by counsel of our choice, even if the suit is groundless, false or fraudulent.” R. 93.
On March 22, 2001, Donegal filed a complaint for declaratory judgment requesting that the court enter a judgment that Done-gal had no duty to defend or indemnify Baumhammers or Parents in the civil actions filed against them by Plaintiffs since the shootings were not accidental in nature but were the result of intentional conduct which the policy did not cover.2 R. 106. Donegal additionally asserted, in the alternative, that if Baumhammers or Parents were entitled to have Donegal defend and potentially indemnify them, the shootings were the result of a single “occurrence.” On September 6, 2001, Donegal filed a *290motion for summary judgment asserting that it was not required to defend or indemnify Baumhammers or Parents. Parents filed cross-motions for summary judgment requesting that the trial court find that Donegal was obligated to defend them and provide indemnification in the event that they are found to be negligent in the actions brought against them by Plaintiffs. Parents additionally asserted that the injuries to each of the individual plaintiffs constituted a separate and distinct “occurrence” for purposes of coverage.
By order dated December 19, 2001, the trial court granted Donegal’s motion with respect to Baumhammers, declaring that Donegal had no duty to defend or indemnify him, and denied Donegal’s motion with respect to Parents, determining that Done-gal did have a duty to defend and indemnify Parents for six individual “occurrences.” On June 6, 2002, following the grant of a motion for reconsideration filed by Done-gal, the trial court reinstated its December 19, 2001 order.
On appeal, a panel of the Superior Court initially reversed the trial court’s determination. That decision was withdrawn however and following re-argument en banc, the court affirmed the order of the trial court determining that Donegal was required to provide coverage to Parents and that Baumhammers’ independent acts of shooting each individual victim resulted in six separate “occurrences” for purposes of coverage. This Court then granted Done-gal’s request for allowance of appeal.
Discussion
Preliminarily, we note that “[t]he interpretation of an insurance contract regarding the existence or non-existence of coverage is ‘generally performed by the court.’ ” Minnesota Fire and Cas. Co. v. Greenfield, 579 Pa. 333, 344, 855 A.2d 854, 861 (2004). “The interpretation of an insurance contract is a question of law, our standard of review is de novo, thus, we need not defer to the findings of the lower tribunals. Our scope of review, to the extent necessary to resolve the legal question before us, is plenary.” Kvaerner Metals Div. of Kvaerner U.S., Inc. v. Commercial Union Ins. Co., 589 Pa. 317, 331, 908 A.2d 888, 893 (2006). Our purpose in interpreting insurance contracts is to ascertain the intent of the parties as manifested by the terms used in the written insurance policy. 401 Fourth Street, Inc. v. Investors Ins. Group, 583 Pa. 445, 454, 879 A.2d 166, 171 (2005). “When the language of the policy is clear and unambiguous, we must give effect to that language.” Kvaerner, 589 Pa. at 331, 908 A.2d at 897. However, “when a provision in the policy is ambiguous, the policy is to be construed in favor of the insured to further the contracts prime purpose of indemnification and against the insurer, as the insurer drafts the policy and controls coverage.” Id.
In determining whether an insurance company is responsible to defend its insured, we observed in Gene’s Restaurant Inc. v. Nationwide Ins. Co., 519 Pa. 306, 308, 548 A.2d 246, 247 (1988) that:
[a]n insurer’s duty to defend an action against the insured is measured, in the first instance, by the allegations in the plaintiffs pleadings.... In determining the duty to defend, the complaint claiming damages must be compared to the policy and a determination made as to whether, if the allegations are sustained, the insurer would be required to pay resulting judgment.... [T]he language of the policy and the allegations of the complaint must be construed together to determine the insurers’ obligation.
Therefore, “a carrier’s duties to defend and indemnify an insured in a suit brought by a third party depend upon a determina*291tion of whether the third party’s complaint triggers coverage.” Mutual Benefit Ins. Co. v. Haver, 555 Pa. 534, 538, 725 A.2d 743, 745 (1999).
To determine whether Donegal is obligated to defend and potentially indemnify parents in the instant case requires review of the factual allegations contained in the complaint. Plaintiffs allege that Parents acted negligently in failing to take possession of Baumhammers’ gun and/or alert law enforcement authorities or mental health care providers about his dangerous propensities.3 It is upon this assertion of negligence that Plaintiffs seek recovery against Parents. Therefore, we are asked to determine whether the alleged negligence of Parents and the injuries resulting therefrom qualify as an “accident” obligating Donegal to defend Parents.
Relying on our decision in Gene’s Restaurant, Donegal asserts that the deaths and injury to the victims in the instant case were the direct product of Baumham-mers’ criminal conduct and injuries that result from intentional acts of wrongdoing do not qualify as “accidental” for purposes of coverage. In Gene’s Restaurant, the insurance company refused to defend the insured restaurant against an allegation by a customer of willful and malicious assault. We reasoned that the assault against the customer was not an accident but an intentional tort. Because the insurance policy precluded recovery for intentional torts, we concluded that the insurer owed no duty to defend. Gene’s Restaurant, 519 Pa. at 308, 310, 548 A.2d at 247.
Donegal argues that because Baumham-mers was found, in a separate criminal proceeding, to have engaged in intentional criminal conduct, it is not required to defend Parents. While Donegal is correct that intentional conduct may not qualify as “accidental,” the complaint in the instant case contains allegations of negligence on the part of the insured. Our conclusion in Gene’s Restaurant that injuries caused by intentional conduct are not “accidental” does not absolve an insurer of the duty to defend its insured when the complaint filed against the insured alleges that the intentional conduct of a third party was enabled by the negligence of the insured.4 Therefore, in the instant case where Plaintiffs have asserted negligence on the part of the insured, our holding in Gene’s Restaurant is not dispositive. Instead, we find applicable our rationale in Mohn v. Am. Casualty Co. of Reading, 458 Pa. 576, 326 A.2d 346 (1974) and the Third Circuit decision in Nationwide Mutual Fire Ins. Co. v. Pipher, 140 F.3d 222 (3d. Cir.1998).
While the facts in Mohn are somewhat different, the analysis is applicable to the instant case. In Mohn, the dependent son of the insured was shot and wounded by police while attempting to flee from the scene of a burglary that he was in the process of committing. The injury to insured’s son ultimately resulted in his death, and the insured sought reimbursement from his insurer for the expenses incurred as a result of his son’s hospitalization. We determined that the decedent sustained an “accidental” bodily injury specifying that “the fact that the event causing the injury may be traceable to an *292intentional act of a third party does not preclude the occurrence from being an ‘accident.’ ” Mohn, 458 Pa. at 579, 326 A.2d at 348. We further observed in Mohn that “the test of whether injury is a result of an accident is to be determined from the viewpoint of the insured and not from the viewpoint of the one that committed the act causing the injury.” Id.
In Pipher, the insured who owned a rental unit failed to install doors on the second floor apartment of the property before leasing it to a tenant. The tenant was murdered in the apartment and the spouse of the decedent brought an action against the insured property owner raising numerous allegations of negligence. The insurance company sought a declaration that because the victim’s death was caused by the intentional acts of a third party, no “accident” or “occurrence” had occurred and therefore Nationwide had no duty to defend or indemnify its insured. The Third Circuit reasoned however that an insurance company has a duty to defend its insured against complaints alleging negligent conduct on the part of the insured and that although a third party may have intentionally injured or killed the plaintiff, the death or injury may still be deemed to be an accident under the terms of the policy. Pipher, 140 F.3d at 225-26. In the instant case, as in Pipher and Mohn, we agree with the Superior Court that our case law requires Donegal to defend Parents against Plaintiffs’ claims of negligence even where that alleged negligence may have led to the intentional acts of a third party.
To determine whether Donegal has a duty to defend its insured in the actions brought by Plaintiffs it is necessary for this Court to examine whether the injuries that are the impetus of the action were caused by an “accident” so as to constitute an occurrence under the policy. The Donegal homeowners insurance policy provides no definition of the term “accident.” However, we have established that the term “accident” within insurance polices refers to an unexpected and undesirable event occurring unintentionally, and that the key term in the definition of the “accident” is “unexpected” which implies a degree of fortuity. Kvaerner, 589 Pa. at 333, 908 A.2d at 898. An injury therefore is not “accidental” if the injury was the natural and expected result of the insured’s actions. See Lower Paxton Twp. v. U.S. Fidelity and Guar. Co., 383 Pa.Super. 558, 567, 557 A.2d 393, 398 (1989) (“[An] [a]ccident is an event that takes place without one’s foresight or expectation. It is an undesigned, unexpected event. The term accident within the meaning of an insurance policy is an event happening by chance unexpectedly taking place. It is the opposite of something likely to occur, foreseeable in due course.”). See also Minnesota Fire and Cas. Co. v. Greenfield, 579 Pa. 333, 359, 855 A.2d 854, 870 (2004) (“ ‘Accident’ has been defined in the context of insurance contracts as an event or happening without human agency or, if happening through such agency, an event which, under circumstances, is unusual and not expected by the person to whom it happens.”) (citations omitted).
This Court has previously addressed whether the circumstances leading to an injury qualify as “accidental” for purposes of insurance coverage. In Kvaemer, this Court was asked to determine whether an insurance company was obligated to defend and indemnify its insured against an allegation of “property damage” caused by the insureds defective workmanship. In determining whether claims of defective workmanship constituted an “occurrence,” and therefore an “accident” pursuant to the policy, we concluded that the definition *293of “accident” could not be satisfied by claims based upon faulty workmanship since such claims did not present the degree of fortuity contemplated by the definition of the term “accident.” Kvaerner, 589 Pa. at 333, 908 A.2d at 898. In Pi-pher, the Third Circuit was asked to determine whether the death of a tenant following the failure of the insured property owner to install doors on the apartment constituted an “accident” for purposes of coverage. Reasoning that from the perspective of the insured, the death of the tenant was unexpected and entirely fortuitous, the Court held the injury to the victim constituted an accident entitling the insured property owner to coverage. Pipher, 140 F.3d at 226.
In the instant case, as in Kvaemer and Pipher, we are required to determine whether, from the perspective of the insured, the claims asserted by Plaintiffs present the degree of fortuity contemplated by the ordinary definition of “accident.” We hold that they do. The extraordinary shooting spree embarked upon by Baum-hammers resulting in injuries to Plaintiffs cannot be said to be the natural and expected result of Parents alleged acts of negligence. Rather, Plaintiffs’ injuries were caused by an event so unexpected, undesigned and fortuitous as to qualify as accidental within the terms of the policy. Because the alleged negligence of Parents resulted in the tragic accidental injuries to the individual plaintiffs, Donegal is therefore required to defend Parents.
Our next inquiry is whether, under the Donegal insurance policy, the injuries to the six individual victims constituted six separate “occurrences” or one single “occurrence” in order to ascertain the limits of liability coverage. There are two key competing approaches for determining the number of occurrences for purposes of liability: (1) the “cause” approach, and (2) the “effects” approach. The prevailing view looks to the “cause” or “causes” of the damage to determine the number of occurrences. Nicor, Inc. v. Associated Elec. and Gas Ins. Services Ltd., 223 Ill.2d 407, 419, 307 Ill.Dec. 626, 860 N.E.2d 280, 287 (2006). Courts that employ this “cause” theory consider whether there is a single cause or multiple causes for the losses sustained. Conversely, courts that employ the “effects” approach calculate the number of occurrences by looking to the effect of the accident or, in other words, how many individual claims or injuries resulted therefrom. The “effects” approach has been applied by a minority of courts.5
*294Although this Court has not addressed the issue, our appellate courts have consistently concluded that the “cause” theory represents the approach that the courts of this Commonwealth should follow. In order to properly understand the cause of loss theory as interpreted and applied in Pennsylvania, it is necessary to consider the principal appellate court cases in which this doctrine has been employed.
In D’Auria v. Zurich Ins. Co., 352 Pa.Super. 231, 507 A.2d 857 (1986), the Superior Court was asked to determine whether the failure of a physician to diagnose and later treat a condition, which resulted in his patient suffering from renal failure, qualified as a single “occurrence.” The Superior Court, relying on the Third Circuit’s analysis in Appalachian Ins. Co. v. Liberty Mutual Ins. Co., 676 F.2d 56 (3d. Cir.1982), adopted the cause of loss test to determine the number of occurrences present. Reasoning that the physician’s misdiagnosis and mishandling of his patient was the cause of the renal failure, the court concluded that for purposes of insurance coverage, only one occurrence had occurred, declining to divide the doctor’s initial failure to diagnose and subsequent failure to treat into multiple occurrences.
In General Accident Ins. Co. of Am. v. Allen, 708 A.2d 828 (Pa.Super.Ct.1998), the Superior Court was asked to determine the extent of the insurer’s obligation to defend and indemnify in a tort case where the insured, Eugene Allen, was accused of abusing three minor children and his wife, Elizabeth Allen, was accused of allowing the abuse to happen or failing to take steps to prevent it. The court noted that the controlling approach to determining the number of occurrences lay in the application of the “cause” approach, and reasoned that with respect to Elizabeth Allen the injury to the three minor children was caused by her failure to prevent the sexual abuse and that her negligence therefore constituted one “occurrence” under the policy. Allen, 708 A.2d at 834.
We agree with the Superior Court’s adoption of the “cause” approach for determining what constitutes an “occurrence” pursuant to an insurance policy. In the instant case, applying the “cause” test, the Superior Court concluded that Parents’ allegedly negligent acts resulted in six distinct attacks on six individuals which constituted six separate “occurrences.” In reaching its determination, the Superior Court found persuasive the rationale of the Florida Supreme Court in Koikos v. Travelers Ins. Co., 849 So.2d 263 (Fla.2003). In Koikos the Florida court reasoned that where the insured owned a restaurant in which an individual shot several victims, the “occurrence” should be defined by the immediate injury-producing act and not by the underlying tortuous omission. Accordingly, the court concluded that the immediate causes of the injuries were the intervening intentional acts of the shooter and therefore each shooting constituted a separate occurrence. The court found no merit to the insurance company’s argument that the injuries to the victims were the result of their exposure to the harmful condition created by the restaurant owner’s negligence in failing to keep his property safe, opting instead to focus on the immediate cause of the damage rather than the underlying negligence of the insured. Koikos, 849 So.2d at 271-72.
Relying on Koikos, the Superior Court in the instant case reasoned that Parents’ *295liability was not triggered until their negligence led to Baumhammers’ shooting rampage. Therefore, the court concluded that Baumhammers’ independent acts of shooting each of his victims constituted the immediate injury-producing act and that the alleged negligence of Parents resulted in six distinct attacks on six individuals. We disagree with the application of the cause approach adopted by the Superior Court in the instant case and the Florida court in Koikos, and conclude instead that to determine the number of “occurrences” for which an insurance company is to provide coverage, the more appropriate application of the cause approach is to focus on the act of the insured that gave rise to their liability.
In Washoe County v. Transcontinental Ins. Co., 110 Nev. 798, 878 P.2d 306 (1994), numerous children brought an action against Washoe County for negligently licensing a daycare center at which an employee sexually abused the children over a three year period. In determining the number of “occurrences” for which the county’s insurance company was required to provide indemnification, the court reasoned that where the insured is not accused of direct or vicarious responsibility for the actual misconduct of another but is accused of some inaction or inadequate action, even though the actions of an individual wrongdoer are the most direct causes of harm for the victims, the action of the individual wrongdoer taken alone is not the basis of liability. Instead, the Nevada court reasoned that liability was premised on the insureds negligence in performing a duty, which permitted the intervening conduct of those who actively caused the victims harm. Therefore, the court explained “the focus of the inquiry should not be on the number, magnitude, or time of the injuries, but rather on the cause or causes of the injury.” Washoe, 110 Nev. at 801, 878 P.2d at 308. The court reasoned that as long as the injuries stemmed from one proximate cause there is a single occurrence, and that because each of the separate instances of molestation arose from the same proximate cause, i.e. the County’s alleged negligence, that negligence constituted a single occurrence for purposes of liability. Id.
We find the rationale of the Nevada Supreme Court persuasive. Parents liability in the instant case is premised on their negligence in failing to confiscate Baum-hammers’ weapon and/or notify law enforcement or Baumhammers’ mental health care providers of his unstable condition. Because coverage is predicated on Parents’ inaction, and the resulting injuries to the several victims stem from that one cause, we hold that Parents’ alleged single act of negligence constitutes one accident and one occurrence.
We are not alone in this decision. Courts in other jurisdictions have reached the same conclusion in similar cases. In Bomba v. State Farm Fire & Casualty Co., 379 N.J.Super. 589, 879 A.2d 1252 (2005), a case factually similar to the instant matter, the son of the insured shot two police officers multiple times. The police officers subsequently sued the insured parents for negligently keeping firearms in their home and negligently supervising their son. Bomba, 379 N.J.Super. at 592, 879 A.2d at 1253. The New Jersey Superior Court reasoned that applying the “cause” approach, the only cause that would support coverage for the police officers’ claims was the negligence of the insured. The court noted that if the action of the gunman was the cause of the injuries, then the officers’ claims would fail by virtue of the policy’s exclusion for intentional or criminal acts. The court thus concluded that there was only one occurrence cognizable under the insurance poli*296cy, namely the negligence of the gunman’s parents. Id. at 596, 879 A.2d at 1255.
In RLI Ins. Co. v. Simon’s Rock Early College, 54 Mass.App.Ct. 286, 765 N.E.2d 247 (2002), a student of Simon’s Rock College embarked on a shooting rampage resulting in the death of two individuals and injury to four others. In a negligence action brought against the college, the court reasoned that in determining the cause of the injuries, the focus was on the cause or occurrence giving rise to insurance coverage. Since the underlying claims against the college were for its allegedly negligent act or omission in failing to prevent the shooter from using his gun, the court concluded that the college’s negligence constituted the “occurrence” for purposes of determining liability under the policy. Noting that the issue to be determined was not liability, but the contractual obligation of the insurer to the insured, the Massachusetts court observed that “since the policy was intended to insure the college for its liabilities, the occurrence should be an event over which the college had some control. Otherwise, with the covered risks out of the insured’s hands and coverage for losses determined by the acts of the unfettered shooter, the insurer would have no basis for setting premiums ex ante and the insurance contract would be illusory.” RLI, 54 Mass.App.Ct. at 290, 293, 765 N.E.2d at 251, 253. See also Travelers Indem. Co v. Olive’s Sporting Goods Inc., 297 Ark. 516, 764 S.W.2d 596 (1989) (where victims of a shooting spree brought a claim against an insured sporting goods store for negligently selling firearms to the gunman, the court reasoned that to conclude that each of the injuries required separate coverage under the policy would put a no-limit policy into effect and held that there was only one occurrence within the meaning of the insurance policy); Home Indem. Co. v. City of Mobile, 749 F.2d 659 (11th Cir.1984) (finding that the intervening negligence of the insured constituted the occurrence that created the liability and that the term “occurrence” did not refer to the damages sustained by each individual plaintiff).
Determining the number of occurrences by looking to the underlying negligence of the insured recognizes that the question of the extent of coverage rests upon the contractual obligation of the insurer to the insured. Since the policy was intended to insure Parents for their liabilities, the occurrence should be an event over which Parents had some control. See RLI, 54 Mass.App.Ct. at 293, 765 N.E.2d at 252. Parents’ alleged negligence in failing to remove Baumhammers weapon and/or alerting the authorities as to his dangerous propensities is the “occurrence” that began the sequence of events that resulted in the eventual injuries to Plaintiffs. In this case, the fact that there were multiple victims does not determine the limits of Parents liability coverage; the number of occurrences does. Although this is a disturbing case with tragic consequences, we are compelled to conclude that Parents’ alleged negligence constituted but a single “occurrence” for purposes of coverage under the Donegal insurance policy. Thus, we reverse the Superior Court’s finding that Donegal is required to provide coverage for six separate occurrences.
Justices CASTILLE, SAYLOR and EAKIN join the opinion.
Chief Justice CAPPY files a concurring and dissenting opinion.
Justice BAER files a concurring and dissenting opinion.