Smoke and flames poured from two abandoned buildings in City Heights as firefighters tried to control the blaze Tuesday evening.
Crews rushed to the small homes at 50th Street and University Avenue at about 5:15 p.m. At least three fire engines lined the street nearby.
Firefighters doused the flames within 30 minutes, but they are still trying to determine the cause.
Witnesses reported seeing someone running from the scene, but the San Diego Fire-Rescue captain said it is too early to put out a description of a possible person of interest.
He said he is glad the fire was put out quickly because it had the potential to spread to thick brush, wooden fences and apartments around it.
No injuries were reported.
