Marguerite L. Dillard appeals from a judgment of the Superior Court for Pierce County affirming an *462order of the Board of the Washington Public Employees' Retirement System which had denied Mrs. Dillard a duty disability award for which she had applied pursuant to the provisions of RCW 41.40.200. We reverse and remand with instruction to award Mrs. Dillard a duty disability award effective June 1, 1974.
RCW 41.40.200 provides:
Subject to the provisions of RCW 41.40.310 and 41.40-.320 [not herein applicable], upon application of a mem: her, or his employer, a member who becomes totally incapacitated for duty as the natural and proximate result of an accident occurring in the actual performance of duty, while in the service of an employer, without wilful negligence on his part, shall be retired: Provided, The medical adviser after a medical examination of such member made by or under the direction of the said medical adviser shall certify in writing that such member is mentally or physically totally incapacitated for the further performance of his duty to his employer and that such member should be retired: Provided further, That the retirement board concurs in the recommendation of the medical adviser: And provided further, No application shall be valid or a claim thereunder enforceable unless filed within two years after the date upon which the injury occurred.
(Italics ours.)
All parties to this appeal accept the fact that Mrs. Dillard became totally incapacitated for duty as a result of her work efforts over the last 4 years of her employment at Western State Hospital at Steilacoom, Washington. The board specifically found that
Ms. Dillard became totally incapacitated for duty as a natural and proximate result of the tension and strain placed upon her by her work over a period of years.
The only issue presented by this appeal, therefore, is whether "the tension and strain placed upon her by her work" constituted an "accident" within the meaning of RCW 41.40.200. Neither the term "accident" nor the term "injury" is defined in RCW 41.40. Both the board and Mrs. *463Dillard direct our attention to, and urge upon us, the definition of that term set forth in Viking Automatic Sprinkler Co. v. Pacific Indem. Co., 19 Wn.2d 294, 142 P.2d 394 (1943). We accept their invitations.
In Viking Automatic Sprinkler Co., the court interpreted a liability insurance policy which provided coverage for liability imposed upon the assured for damages '"caused solely and directly as a result of an accident'" (italics ours) occurring during the life of the policy. The defendant company denied coverage, despite plaintiff's acknowledged liability for damages, on the theory that "the damage was not caused by an accident as contemplated by" the policy. Viking Automatic Sprinkler Co., at 295, 296.
The term "accident" was not defined in the policy and the court accepted two of the definitions then found in Webster's New International Dictionary (2d ed. 1957).
(a) "an undesigned, sudden, and unexpected event";
(b) "a mishap resulting in injury to a person or damage to a thing."
Viking, at 297.
The record in the case at bench establishes that in 1970 Mrs. Dillard was recruited to work on a ward "M" of Western State Hospital as a ward attendant caring for "patients from all institutions over the State that were violent, suicidal, and self-destructive." The chief psychologist of the hospital, who directed the program, described ward "M" as
the toughest ward in the entire hospital, and the typical duties were cleaning up blood and glass, trying to prevent the patients from hurting each other, and the staff; and it was sort of a part of everyday routine to get beat up, the staff to get beat up, choked out, . . .
Mrs. Dillard testified that within the first half hour of her employment on ward "M", a patient "came up and stomped on my foot right across the instep." She explained that being physically accosted by patients "was a daily thing, almost." On one occasion, a patient in the dining room
*464tipped over six tables and hurt two other patients and attacked me, and of course the men came and got him right away; this went on for two or three weeks, every-time they would bring him in the dining room; . . .
The director of the program related an incident in which a patient, grappling with Mrs. Dillard, caused both of them to be tossed over a fourth floor parapet. The patient fell to her death to the concrete below, and "Mrs. Dillard was hanging onto the rail when we rescued her." He also described the emotional trauma accompanying events such as, "We had one girl bite the ear off another and eat it" and, "We had one boy put his fist through 256 windows in 72 hours; thirty-eight stitches, he started again."
A clinical psychologist diagnosed Mrs. Dillard's condition as "psycho-physiologic reaction to anxiety," and that her disability in 1974 was caused by "being around violent patients, especially who were unpredictable." He also explained that Mrs. Dillard had a history of physical problems which have a strong neurotic component, and that her employment at Western State Hospital "seriously aggravated the neurotic process."
There is no doubt in our minds that each of the events which Mrs. Dillard encountered on a day-to-day basis, singly, constituted an "accident" within the meaning of Viking Automatic Sprinkler Co., and within the meaning of RCW 41.40.200. Furthermore, all of these events, collectively, over a period of 4 years, constituted a series of "accidents" which caused Mrs. Dillard's "total incapacity for duty."
The board insists, however, that Mrs. Dillard did not sustain an "accident" because all of these events, though they admittedly produced stresses and strains which caused her disability, and which would ordinarily be considered abnormal and unusual, "were routine in the twisted world of the mental hospital."
Armed with this "normal routine duties of a job" argument, the board directs our attention to a long series of so-called "heart attack" cases in this and other jurisdictions *465which deny claims for "injury" or "accident" under workmen's compensation or retirement statutes on the theory that a routine act not involving unusual exertion on the part of an employee does not constitute an injury.
Mrs. Dillard is not suffering from a malfunction of her heart; hence, those cases are inapposite. In Boeing Co. v. Fine, 65 Wn.2d 169, 171, 396 P.2d 145 (1964), the court expressly declared that "under currently persuasive medical theory" an "unusual exertion" was necessary to satisfy the definition of injury to the heart. However, the court refused to extend this "unusual exertion" requirement to establish an injury to other parts of the body.
We conclude that the board applied an erroneous standard of law with which to measure the term "accident” as contemplated by RCW 41.40.200. Thus, the board committed an error of law. Applying the appropriate standard of law from Viking Automatic Sprinkler Co. to the facts at bench, we conclude that Mrs. Dillard's total incapacity was caused by an accident.
Judgment reversed with direction to award Mrs. Dillard a duty disability award effective June 1, 1974, less the cumulative amount of awards previously paid.
Pearson, C.J., concurs.