STEUBENVILLE — The man whose body was found by firefighters investigating a structural fire at 618 Brady Ave. on Sunday died of natural causes, the Jefferson County Coroner’s Office reported.

The 74-year-old male, identified Monday as Raymond Mills, had a history of health issues, the coroner’s office said.

“He was not a fire victim,” a spokesperson for the coroner’s office reported. “He was a 74-year-old person with significant health problems who had an apparent heart attack.”

Fire Chief Carlo Capaldi said the fire “had burned itself out” by the time police and firefighters arrived on scene around 8 p.m. Sunday.

“The fire ran out of oxygen and was already out on our arrival,” Capaldi said.

“We did a search of the house and found one (individual) who lived there, one person and one dog,” he added.

A family member who had gone to the residence to check on the man realized there had been a fire, authorities said.

Capaldi said the fire is still under investigation.