A neighbor reported the fire at Brooks' home at 319 Drayton Court shortly before 2:30 p.m., Contra Costa County Fire Protection District Battalion Chief Ben Smith said.
When firefighters arrived, they saw brown smoke coming from the gable vents on the second floor of the house, fire district spokesman Lewis Broschard said.
When they opened the door, firefighters were met with thick black smoke inside the home, Broschard said.
Firefighters were told that Brooks lived alone in the house and immediately began searching for him.
They found him the floor of an upstairs bedroom where the fire was burning. He was pronounced dead at the scene, Broschard said.
An autopsy determined that Brooks died from smoke inhalation, according to the coroner's office.
Brooks' cat also died in the fire, Smith said.
The cause of the fire is still under investigation.
The blaze was confined to the one bedroom, but smoke and flames caused "moderate structural damage and significant smoke damage" throughout the house, according to the fire district. The damage is estimated at $150,000.