MARTINEZ (CBS SF) - Investigators were still trying to determine the cause of a fatal fire at a home in Martinez early Tuesday morning.

A neighbor reported the fire at a house on the 3800 block of Martha Drive at about 4:45 a.m., Contra Costa County Fire Protection District Fire Marshal Lewis Broschard said.

When firefighters arrived, they found smoke and flames coming out of the home's front windows, Broschard said.

Neighbors told firefighters that someone was inside the house, but by the time firefighters found him he was already dead.

The Contra Costa County coroner's office was still working to confirm the victim's identity late Tuesday morning.

It took firefighters about 20 minutes to control the blaze, which caused an estimated $100,000 in damage, Broschard said.

Crews remained at the scene until about 6:15 a.m. extinguishing hot spots.

Broschard said the house was being renovated in preparation for sale and that there were no smoke detectors anywhere inside.

No other injuries were reported, Broschard said.

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