Walker L. Stringer, Jr. purchased a bus ticket in Augusta from Travel, Inc. of South Carolina on June 13, 1989 and boarded a bus owned and operated by Southeastern Stages, Inc. Shortly before the bus reached its Atlanta destination, he was shot and killed in an unprovoked attack by Perry Tyrone Irvin, a fellow passenger. Summary judgment was granted to Southeastern, its insurer, and Travel in the wrongful death action brought by Stringer’s parents and the representative of his estate (the Stringers). A plurality of the Court of Appeals reversed the trial court. Stringer v. Southeastern Stages, 207 Ga. App. 223 (427 SE2d 494) (1992). We reverse the Court of Appeals.
A common carrier of passengers is not an insurer of the safety of its passengers, but must exercise extraordinary diligence to protect the lives and persons of its passengers. OCGA § 46-9-132. Extraordinary diligence is defined as “that extreme care and caution which very prudent and thoughtful persons exercise under the same or similar circumstances.” OCGA § 51-1-3; East Tenn. &c. R. Co. v. Green, 95 Ga. 736, 737 (22 SE 658) (1895).
Construed in favor of the Stringers, the evidence reflects that Southeastern knew about two separate occasions, in 1986 and 1988, in which a knife-wielding passenger had assaulted a bus driver while the bus was in transit. At the time of the 1989 incident in issue, Southeastern and its agent, Travel,1 had made no changes in the security measures employed to enforce rules prohibiting passengers from boarding buses with deadly weapons, relying only on visual inspections of embarking passengers. When Irvin purchased his bus ticket, he informed the ticket agent that there “probably would be an undercover cop . . . looking for him” and that the agent should “tell them that he hadn’t seen [Irvin].” Irvin later returned to the ticket agent to remind him not to “forget what I told you.” The evidence before the trial court on summary judgment reflects that Irvin passed the *642driver’s visual inspection and that his behavior remained unremarkable until he suddenly began firing on other passengers at the end of the trip.
Irvin’s comments to the ticket agent and behavior before his unprovoked criminal actions on the bus, in and of themselves, are not sufficient to indicate that Irvin was anything more than a practical joker or a harmless eccentric. Hence, this evidence alone fails to raise any question of fact whether defendants, in the exercise of extraordinary diligence, were on notice that Irvin was or might be a danger to the carrier’s passengers. See Savannah &c. R. Co. v. Boyle, 115 Ga. 836 (42 SE 242) (1902); Pinnell v. Yellow Cab Co., 77 Ga. App. 73 (47 SE2d 774) (1948). However, the Stringers argue and the Court of Appeals held that because Southeastern knew about the 1986 and 1988 assaults, a question of fact exists whether the defendants reasonably should have anticipated criminal activity in general, thus calling into question the adequacy of the security measures taken to prevent or mitigate such danger and the interpretation to be given Irvin’s unusual comments.2 In so holding, the Court of Appeals did not apply common carrier law but instead relied exclusively on appellate decisions addressing OCGA § 51-3-1 and the duty an owner or occupier of land owes to invitees.
We disapprove that language in the Court of Appeals’ opinion applying premises liability law to common carrier cases. The rule applicable in common carrier cases is that
whenever a carrier, through its agents or servants, knows or has opportunity to know of a threatened injury, or might have reasonably anticipated the happening of an injury, and fails or neglects to take the proper precautions or to use proper means to prevent or mitigate such injury, the carrier is liable. ... It is [the common carrier’s] duty to use proper care and vigilance to protect [passengers] from injuries by such persons that might reasonably have been foreseen and anticipated. . . . Knowledge of the passenger’s danger, or of facts and circumstances from which that danger may reasonably be inferred, is necessary to fix the carrier’s liability in this class of cases. . . . [The carrier] is not regarded as an insurer of his passenger’s safety against every possible source of danger; but he is bound to use all such reasonable precautions as human judgment and foresight are capable of, to *643make his passenger’s journey safe and comfortable.
(Punctuation omitted.) Boyle, supra at ,838-839.
There are situations where prior violent activity can serve to place a common carrier on notice to anticipate such violence and, pursuant to the carrier’s duty of extraordinary diligence, to protect its passengers from that violence. See Metropolitan Transit System v. Burton, 103 Ga. App. 688 (120 SE2d 663) (1961) and Ga. R. &c. Co. v. Murphy, 28 Ga. App. 173 (1) (110 SE 680) (1922) (carrier aware of prior violent and disorderly behavior of others in entering street cars at street car stop under a duty to anticipate such behavior and to protect passengers from that behavior). A common carrier’s knowledge of a threatened danger is not restricted to knowledge that a particular individual possesses dangerous propensities,3 since there are situations where a common carrier can reasonably anticipate misconduct without knowing which individual will misbehave, as, for example, in a situation where a particular route has a history of violent and assaultive conduct by passengers, such that violent incidents occur daily or weekly. See, e.g., Lopez v. Southern Cal. Rapid Transit, 710 P2d 907 (Cal. 1985). To hold, as Southeastern urges, that a carrier is absolved from liability unless it possesses knowledge of a particular individual’s dangerous propensities would run contrary to well-established Georgia law that a carrier has a duty to use “all such reasonable precautions as human judgment and foresight are capable of” to protect its passengers. Boyle, supra.
However, a common carrier is not required to take measures to protect its passengers from the intentional misconduct of third persons until something occurs to put the carrier on notice that such conduct might be reasonably anticipated. Paschal v. Ferguson Transport, 189 Ga. App. 447, 448 (375 SE2d 901) (1988). To establish reasonable foreseeability, more than the mere possibility of an occurrence must be shown, since otherwise a common carrier would be made an insurer, with absolute liability to all passengers. See Boyle, supra at 839. Accordingly, we hold that “ ‘(k)nowledge of conditions which are likely to result in an assault upon a passenger, or which constitute a source of potential danger, imposes the duty of active vigilance on the part of the carrier’s agents and the adoption of such steps as are warranted in the light of existing hazards.’ [Cit.]” Gordon v. Chicago Transit Auth., 470 NE2d 1163, 1168 (Ill. App. 1984).
*644Applying these principles to the case at bar, we do not agree with the Court of Appeals that Southeastern’s knowledge of two assaults on bus drivers by knife-wielding passengers in 1986 and 1988 raised a question of fact whether Southeastern knew, had the opportunity to know, or could reasonably have anticipated the violent action of Irvin against the decedent. Although the prior incidents alerted Southeastern that violent passengers presented a “possible source of danger” to other passengers, Boyle, supra at 839, there was no evidence that conditions existing on the Augusta-Atlanta route travelled by the decedent were likely to expose passengers to a reasonably foreseeable danger. As noted earlier, Irvin’s comments and behavior alone were not sufficient to create a fact question whether Southeastern failed to exercise the extraordinary diligence required of it. Accordingly, as no fact questions remain whether Southeastern breached its duty to use “all such reasonable precautions as human judgment and foresight are capable of,” Boyle, supra at 839, to protect the Stringers’ decedent, the trial court correctly granted summary judgment to defendants.4
Judgment reversed.
All the Justices concur, except Judge Lowrey S. Stone, who dissents. Carley, J., disqualified.