FRESNO, Calif. -

State workplace safety officials are investigating the deaths of a farm worker and construction worker as possibly heat-related.

The state's Division of Occupational Safety and Health reported Friday that a 30-year-old farmworker who had been working at a watermelon field southwest of Fresno near Coalinga died on Tuesday.

The 55-year-old construction worker died last Friday in Yuba City, north of Sacramento.

The deaths occurred while the state was in the grip of a heat wave that sent temperatures into the triple digits.

State officials say coroners are still trying to determine the cause of death.

A 77-year-old man was found dead in his mobile home in Ceres, south of Modesto, on Tuesday night and an autopsy determined the cause was heat.