Appellant seeks to recover from respondent Firemen’s Retirement Fund, death benefits allegedly payable on account of the death of her husband, John L. Branson, herein sometimes referred to as Branson.
February 6, 1947, Branson commenced working as a paid fireman for the City of Pocatello. June 29, 1947, he received an injury to his right knee caused by an accident arising out of and in the course of said employment. He was totally disabled for work on account of such injury from January 15, 1948 to July 25, 1951.
July 25, 1951, Bannock County employed Branson as a deputy sheriff; he served in that capacity until and including March 1, 1952. The City of Pocatello then reemployed him March 2, 1952, as a paid fireman, and he so served until August 31, 1952, when the city terminated his employment. Bannock County then reemployed him September 1, 1952, in .the sheriff’s office where he served until November 7, 1953. He was not thereafter employed. His death occurred December 30, 1953.
July 2, 1947, Branson, by claim filed with the Industrial Accident Board, claimed, and April 15, 1952, by compensation agreement approved by', the Board, was awarded, compensation u'nder the Workmen’s Compensation Law for his total disability for work ón account of such injury, for the period from January 15, 1948 to July 25, 1951, and specific indemnity for a resultant permanent injury.
November 14, 1949, Branson, by claim filed with the Board, also claimed, and June 12, 1952, by agreement approved by the Board, was awarded, benefits under the Firemen’s Retirement Fund payable during a portion of the period he was incapacitated from serving as a paid fireman on account of such injury. He received payment of such benefits from March 4, 1949, the effective date of amendment of I.C., sec. 72-1414, to July 25, 1951, less reduction by the amount he had received during said time under the Workmen’s Compensation Law on account of his incapacitation, as so provided by I.C., sec. 72-1414(B).
March 7, 1953, Branson by claim filed with the Board, claimed additional benefits under the Firemen’s Retirement Fund.
November 13, 1953, Branson filed with the Board his petition for additional compensation under the Workmen’s Compensation Law and for additional benefits under the Firemen’s Retirement Fund. Respondent State Insurance Fund by its answer, inter alia, pleaded the bar of the statute of limitations under .the Workmen’s Compensation Law, i. e., I.C., sec. 72 — 407, which allows four years from the date of the accident causing the injury, for hearing of a claim under the Workmen’s Compensation Law upon which compensation has been paid and discontinued; and I.C.,.sec. *17172-607, which allows four years from the date of the accident causing the injury within which to apply for modification of an award on the ground of change in condition. The Board treated Branson’s petition as an application for modification because of changed condition and, since four years had expired since June 29, 1947, the date of the accident which caused Bran-son’s injury, ruled that any further relief to him was barred. No appeal was taken from such decision within 30 days or at all as provided by I.C., sec. 72-608.
August 7, 1954, appellant filed with the Board her claim for benefits under the Firemen’s Retirement Fund. She alleged the accident of June 29, 1947, and Bran-son’s personal injury thereby received, while working for the City of Pocatello as a paid fireman, and his retirement from such work, and death as attributable to said accident.
Respondent, Firemen’s Retirement Fund, through its administrator, generally denied liability on appellant’s claim; also, in bar to said claim, pleaded res judicata and the statute of limitations, I.C., secs. 72-407, 72-607 and 72-608 of the Workmen’s Compensation Law. The Board, upon hearing the matter, entered an order, October 18, 1955, denying appellant’s claim. Appellant perfected an appeal from such order.
Appellant asserts error of the Board in denying her claim for benefits on grounds of res judicata and the bar of said statute of limitations.
I.C., sec. 72-1414, subdivisions (B) and (C), omitting the provisions relating to reduction by payments received as workmen’s compensation, read as follows:
“(B) Any paid fireman incapacitated- by injury in the course of duty, or by illness attributable wholly or partially to service as a paid fireman, shall be retired so long as such disability shall continue in a degree which prevents efficient service, and during such disability shall be paid from said fund [firemen’s retirement] a monthly sum of ninety-five dollars * * *.
“(C) In the event a paid fireman is killed or sustains injury, from which death results,. while in performance of his duty, and leaves surviving him a widow, his widow shall, during the time she remains his widow and does not remarry, be paid from the said fund the monthly sum of ninety-five dollars ‡ * ‡ »
In regard to respondent’s plea of res judicata the Board’s ruling on Bran-son’s claim filed March 7, 1953, for additional benefits under the Firemen’s Retirement Fund, is as follows:
“This claim [filed March 7, 1953 for additional Firemen’s Retirement Fund benefits] was denied in case No. 248852 [Workmen’s Compensation] by decision *172rendered May 29, 1954. That decision upheld the plea of the defendants, including defendant herein of the bar' of Sections 72-407 and 72-607, specifically as to Branson’s workmen’s compensation claim, inferentially as to his claim against the Firemen’s Retirement Fund.
“ * * * Decedent’s second claim on the Firemen’s Retirement Fund, dated March 4, and filed March 7, 1953, was based solely on the same accident. In fact it was a claim for additional compensation on a change of condition. So also was his petition for hearing filed November 13, 1953. Both were filed after a lapse of more than 51/£ years from the original accident.”
The Board then ruled:
“The facts and circumstances upon which decedent’s widow relies for recovery under subdivision (C) of Section 72-1414 must be such that decedent, had he survived, could have himself sought and obtained recovery under subdivision (B) of said section.”
I.C., section 72-1423 reads:
“All claims against said fund shall be filed with the industrial accident. board of the state of Idaho in as nearly as practicable the same manner that claims under the Workmen’s Compensation Law of the, state of Idaho are filed, and .the .said industrial accident board is hereby given jurisdiction to entertain and pass upon said claims,, allow or deny claims and make awards, and the provisions of the Workmen’s Compensation Law of the state of Idaho relative to process, hearings and appeals are hereby made applicable to the provisions of this act, and said industrial accident board is hereby given power and authority to make rules and regulations governing procedure in relation to said claims.”
I.C., sec. 72-1423 relates only to procedure, i. e., the filing, hearing and determination of claims against the Firemen’s Retirement Fund, with the provisions of the Workmen’s Compensation Law, “relative to process, hearings and appeals,” made applicable. Such section of the statute, while it presupposes the necessity of making a claim for filing and determination, 40 Am. Jur., Pensions, sec. 38, p. 990, does not relate to the substantive right to make the claim, thereby to claim benefits under the Fund. Obviously, a paid fireman, retired or incapacitated, may either claim benefits under the Fund, or abandon that right by his failure to make a claim.
Additionally, I.C., sec. 72-1414(C) grants unto the decedent paid fireman’s surviving widow the' right to claim death benefits <under the Firemen’s Retirement Fund, only in the event her husband is killed,, or sustains injury from which his death results, while in performance of his duty. That right of the widow, does not and cannot exist .during the lifetime of he'r husband, *173and cannot come into existence until his death occurs, nor unless the surviving widow exercises her right to claim those benefits by making and filing a proper claim in the premises. Both claims, i. e., the fireman’s claim and his surviving widow’s claim, cannot exist concurrently, since the rights under each claim exist at different times, independent and separate, the one from the other. The lack of privity between the paid fireman, on the one hand, and the surviving widow, on the other hand, in respect to each respective right to benefits under said Fund becomes clear in view of each such distinct and separate right created and the distinct and separate nature of each such claim.
The right of a widow to pension benefits, under a statute providing for pensions, vests upon the happening of the contingency specified in the statute, that is, the death of the employee or former employee. Vero v. Sacramento City Employees’ R. System, 1940, 41 Cal.App.2d 482, 107 P.2d 82; Chaney v. Los Angeles County P. Officer’s R. Board, 1943, 59 Cal.App.2d 413, 138 P.2d 735; English v. City of Long Beach, 1954, 126 Cal.App.2d 414, 272 P.2d 875; State ex rel. Warren v. City of Miami, 1943, 153 Fla. 644, 15 So.2d 449; Hollis v. Jones, 1937, 184 Ga. 273, 191 S.E. 127; West v. Anderson, 1939, 187 Ga. 587, 1 S.E.2d 671; Arnold v. Browning, 1943, 294 Ky, 164, 171 S.W.2d 239; Meyer v. Board of Trustees of F. Pension & R. Fund, 1942, 199 La. 633, 6 So.2d
713; State ex rel. Bartelt v. Thompson, 246 Wis. 11, 16 N.W.2d 420, appeal dismissed 324 U.S. 828, 65 S.Ct. 868, 89 L.Ed. 1395.
The test of res judicata is the identity of the rights sued for, the identity of the cause of action, and the identity of the parties. Neil v. Hyde, 32 Idaho 576, 585, 186 P. 710; Evans v. Davidson, 57 Idaho 548, 67 P.2d 83; Linder v. City of Payette, 64 Idaho 656, 135 P.2d 440. No one of those tests can be applied successfully in the case here.
The doctrine of res judicata has no application to appellant’s claim for death benefits under the Firemen’s Retirement Fund.
In regard to respondent’s plea of the statute of limitations, I.C., secs. 72-407, 72-607 and 72-608 contained in the Workmen’s Compensation Law, the Industrial Accident Board ruled, by virtue of the provisions of I.C., sec. 72-1423 relating to claims, process, hearing, and appeals, that said sections of the statute so pleaded by respondénts are by reference a part of the Firemen’s Retirement Act.
Such ruling appears correct as: to I.C., sec. 72-608 which provides that in. workmen’s compensation proceedings an. appeal from an award must be taken to, this Court within 30 days after a copy of the award has been sent to the parties. Idaho Const., Art. V, § 9. However, such *174section of the statute has no application in the case here, since, first, Branson’s failure-to appeal from-the Board’s decision of May 29, 1954, in Workmen’s Compensation Case No. 248852, which, the Board held, inferentially involved his Firemen’s Retirement Fund claim, did not render res judicata appellant widow’s claim which came into existence upon Branson’s death; and second, appellant perfected her pending appeal within said time limit.
The Board, while it ruled I.C., secs. 72— 407 and 72-607 are, by reference in I.C., sec. 72-1423 to “claims”, made a part of the Firemen’s Retirement Act, did not rule that either section of the statute barred appellant’s claim. The Board merely ruled that death benefits are not payable to Bran-son’s dependents because his death occurred approximately six and one-half years after June 29, 1947, the date of the accident.
We deem it unnecessary to determine in this proceeding whether I.C., secs. 72-407 and 72-607 in workmen’s compensation matters are made a part of the Firemen’s Retirement Act by the reference in. I.C., sec. 72-1423 to “claims”; for neither section could operate in bar to appellant’s claim for death benefits, even though a part of the Firemen’s Retirement Act, as hereinafter shown.
A portion of I.C., sec. 72-407 provides that where payments of compensation have been made and discontinued a claimant shall have four years within which to petition the Board for a hearing demanding further compensation. Such portion could have no application herein since respondent never paid any benefit to appellant on her claim made against the Firemen’s Retirement Fund.
A further portion of I.C., sec. 72-407 provides that where- claim for compensation has been made and no compensation paid thereon, a claimant shall have one year from the date of making claim within which to petition the Board for a hearing on the claim. Such latterly mentioned portion of the statute could have no application herein because appellant filed her claim for death benefits under the Firemen’s Retirement Fund August 7, 1954 with' the Board. She filed her petition for hearing the claim September 7,. 1954, with the Board, within one year from the date of making the claim, and respondent has never paid any sum under the claim.
I.C., sec. 72-607 provides that a workmen’s compensation claimant seeking modification of an award on the ground of' change in condition must file the application with the Board within four years of the date of the accident causing the injury. Neither appellant’s claim against the Firemen’s Retirement Fund nor her petition for hearing the claim constitute an application for modification of a previous award in her favor.
*175Respondent has failed to plead any statute of limitations, if such there be, in bar of appellant’s claim for benefits under the Firemen’s Retirement Fund. The defense of the statute of limitations may be waived by failure to interpose it. Paull v. Preston Theatres Corporation, 63 Idaho 594, 124 P.2d 562; Rivera v. Johnston, 71 Idaho 70, 225 P.2d 858; Dunn v. Silver Dollar Min. Co., 71 Idaho 398, 233 P.2d 411; Arnold v. Claude Lacey & Son, 73 Idaho 1, 245 P.2d 398.
The remaining question for determination is whether Branson’s death resulted from the accidental injury of his right knee June 29, 1947.
The record shows and the Board found that a giant-cell tumor developed at the site of the knee injury for which Branson received treatment until through the year 1950; early in 1951 the knee was operated by “curettement of the bone cyst and inlay bone graft.” He appeared improved at the time he returned to work the midsummer of 1951, but, as the Board found, “Branson continued to have some trouble, particularly with drainage from his surgical wound. His trouble increased in the middle of 1952.” During November, 1952, he had another bone graft operation in the region of his original injury.
. During February, 1953, malignancy was discovered on laboratory tests, diagnosed as cancer, from which sundry complications developed resulting in his death December 30, 1953. The direct cause of his death was attributed to generalized sarcomatosis, a generalized spread of cancer through his system.
The Industrial Accident Board’s Finding, supported by competent and substantial undisputed evidence, reads:
“The cancer which was the direct cause of Branson’s death developed at the site of his accidental injury, where six months after the accident a benign giant cell tumor was diagnosed. * * * the accident of June 29, 1947, was in all probability an antecedent cause of Branson’s cancer and of his death 61/2 years after the accident.”
The Board then ruled:
“The direct cause of Branson’s death on December 30, 1953, was cancer, * * * at the site of his accidental injury on June 29, 1947, and where within six months after the accident a benign giant-cell tumor had developed. Claimant herein has shown by a preponderance of the evidence to a reasonable degree of probability that Bran-son’s accidental injury of June 29, 1947, was an antecedent cause of his 'cancerous condition and of his ultimate death on December 30, 1953.”
The general rule is, that the only requirement necessary to'establish the dependents’ right to a pension is a showing of causal, connection between the injury and the death. In the case of Biegel v. *176Village of North Hills, 185 Misc. 131, 57 N.Y.S.2d 412, 414, the rule is stated:
“Where there is a direct, causal connection between the injury and the death, even in cases where the decedent was suffering from a serious disease, which injury accelerated or aggravated the condition, the widow and children can recover.”
To the same effect see: Dryden v. Board of Pension Com’rs, 1936, 6 Cal.2d 575, 59 P.2d 104; Bradley v. City of Los Angeles, 1942, 55 Cal.App.2d 592, 131 P.2d 391; Faber v. Board of Pension Com’rs of City of L. A., 1943, 56 Cal.App.2d 825, 133 P.2d 404; Lundrigan v. City of Los Angeles, 1947, 82 Cal.App.2d 238, 186 P.2d 12; Rogers v. Retirement Board, 1952, 109 Cal.App.2d 751, 241 P.2d 611; Smith v. Essex County Park Commission, 1933, 110 N.J.L. 206, 164 A. 395.
The order of the Industrial Accident Board is reversed and the cause remanded to the Board with instructions to enter an award in favor of appellant in accordance with the views herein expressed. Costs to appellant. •
PORTER, TAYLOR and McQUADE, TJ-, concur.