A plumber repairing an upstairs toiler prompted an accidental apartment fire in University City, which quickly spread to the attic and adjoining walls before crews knocked it down.
The fire broke out on the 3900 block of Camino Calma around 1:30 p.m. Thursday, San Diego Fire-Rescue Officials (SDFD) said.
When crews arrived, they could see smoke and fire rising from the second floor of a two-story condominium. Each condominum has four two-story units.
The flames were contained to the one unit, but three other units were damaged by the fire as well.
Crews knocked down the fire in 25 minutes. The unit where the fire broke out suffered heavy fire damage.
Authorities on scene inspected the electricity to make sure it was not compromised in the fire. Once that is completed, residents will be let back into their units.
Fire officials ruled the fire accidental, saying a plumber using a torch to complete repairs in an upstairs bathroom set off the fire.
Sixteen people live in the four units, crews said, five of which live in the unit that suffered the most damage. The local Red Cross will assist those displaced with temporary housing and aid.
The building suffered $400,000 in damage and there was $200,000 in damage to the contents of the unit.
No injuries were reported.
No other information was immediately available.