The fire was reported around 2:30 a.m. Monday on Danecroft Avenue, according to the Los Angeles County Fire Department. Firefighters extinguished the flames in less than an hour.
Officials initially said the man and a dog were found inside the home. He was moved outside and was later pronounced dead.
Another person also died, according to records from the medical examiner, but the identity of that individual has not been released. That individual was found in one of the bedrooms inside the residence.
Lt. Steve Dejong with the L.A. County Sheriff's Department said the couple that lived in the home was in the process of getting divorced, with papers filed just about two weeks ago. They had been married since 1976, and cited irreconcilable differences as reason for the divorce.
Police responded to their home about a month ago for a domestic violence call.
"No one was arrested in that incident," Dejong said. "We were told that it was both parties accusing each other of pushing/shoving."
Authorities declined to comment on whether the man's 68-year-old wife, who was said to be at a local football game Sunday night, is considered a suspect.
The couple has two adult children. Their daughter was at the scene all morning, surrounded by friends and family.
"They are distraught. They are concerned. They're very worried," Dejong added.
The man's death is being called suspicious but it's not yet a homicide investigation.
Dejong confirmed blood was found inside the home. Detectives also said the 71-year-old man had injuries not related to the fire, but did not elaborate on the type of injuries he sustained. The man's official cause of death has not been released.
Neighbor Mike Gregorian said the 71-year-old man was an engineer and helped him fix some issues with his house. He said he hadn't seen him in a while.
The cause of the fire is under investigation.