## Facts

- Ramon O. Marquez worked for Magma Copper Company from October 1955 until shortly before his death in May 1968.
- From October 1955 to mid-May 1958, he worked underground for about 832 shifts and was exposed to harmful quantities of silicon dioxide dust.
- After mid-May 1958, he worked aboveground as a laborer until May 17, 1968, without harmful dust exposure.
- Marquez developed silicosis that caused a longstanding fibrotic lung condition.
- He died on May 30, 1968, of heart failure (cor pulmonale) induced by strain on the heart from the silicosis-related lung condition.
- Silicosis was classified by statute as an occupational disease, but compensability under the occupational disease scheme required 1,200 qualifying shifts of harmful exposure within the ten years before death.
- Because Marquez had only about 832 qualifying shifts, the Industrial Commission denied his widow’s claim for death benefits, and the court of appeals affirmed.

## Issues

1. Whether death from heart failure induced by employment-caused silicosis-related lung fibrosis may be compensable as an “accident arising out of and in the course of employment” even if the statutory occupational disease exposure requirement is not met.
2. Whether occupational disease statutory limitations may bar compensation otherwise required for an accidental injury or death under the constitutional and general workers’ compensation provisions.

## Decision

- The Arizona Supreme Court vacated the court of appeals’ decision and set aside the Industrial Commission’s award denying death benefits.
- The Court held the death was compensable as an industrial accident under the general workers’ compensation law.
- The Court rejected treating the occupational disease statute’s special exposure requirements as an exclusive bar to recovery when the work-related condition results in a compensable accidental death.
- The case was remanded for further proceedings consistent with recognizing compensability.

## Legal Principles

- Arizona’s constitutional compensation guarantee for “any accident arising out of and in the course of employment” must be construed broadly in favor of coverage.
- An “accident” is not limited to a sudden external event; a work-caused condition operating over time may constitute an accident when the harmful result (including death) is unexpected.
- Occupational disease statutes that impose special compensability conditions do not preclude recovery under the general accident-based compensation framework when the employment-related exposure culminates in an accidental injury or death.
- Statutory schemes must be applied consistently with the constitutional mandate and may not be interpreted to defeat constitutionally required compensation for accidental work-related injury or death.

## Conclusion

The court held that a miner’s fatal cor pulmonale caused by work-related silicosis-induced lung fibrosis qualified as a compensable industrial accident, even though the claim did not satisfy the occupational disease statute’s exposure threshold, and it set aside the denial of death benefits.


Marquez v. Indus. Comm’n, 110 Ariz. 273, 517 P.2d 1269 (1974)