SAN FRANCISCO -- Firefighters responding to a fire in the Bayview district Wednesday morning found a dead body, and investigators were calling both the blaze and the death "suspicious."

The incident was being investigated jointly by the city's police and fire departments.

Fire Lt. Mindy Talmadge said firefighters responded to a "fire incident" at 9:12 a.m. at 1719 Quesada Ave. Someone on a cellular phone may have reported the fire, Talmadge said.

Firefighters entered the structure and found a body, Talmadge said. She declined to reveal whether the victim was male or female.

Homicide detectives were called to the scene by the medical examiner, police reported.

The structure suffered "moderate damage" in the blaze, Talmadge said.