Authorities with the San Bernardino County Fire Department said firefighters responded to a two-alarm fire at the 3000 block of N. Arrowhead Avenue at approximately 2:15 a.m.
Responding crews encountered heavy smoke and fire.
Two people were inside the home, where one was pronounced dead.
San Bernardino (final): deceased & injured were 2 male adults. NFI. Press release forthcoming.— SB County Fire (@SBCOUNTYFIRE) November 19, 2018
Firefighters rescued a second man from a bedroom while contending with a partial structural collapse when an air conditioning unit fell through the roof. That person died after being transported to a hospital.
Authorities said the victims were located in separate bedrooms and they appeared to be the only occupants of the home.
Neither was immediately identified by authorities, though neighbors identified the two as a father and his adult son.
Marci Padilla, who lives two doors away on North Arrowhead Avenue, said the two men had lived in the house for more than 20 years and mostly kept to themselves.
"It was just the father, the son, and the only time we ever saw them was when the son was mowing the lawn or they were leaving," Padilla said.
The fire was knocked down in about an hour and investigators said significant damage was done to the Victorian-style home.
Arson investigators were summoned to the scene and were working to determine the official cause of the incident. Fire officials say at this point, they do not believe the fire was suspicious.