A second-alarm fire early Saturday morning damaged the Arlington Apartments, an older building of studio units in the Gaslamp District.
San Diego Fire-Rescue reported the blaze broke out around 3:50 a.m. in the front desk area of the 89-unit building at 701 7th Avenue.
A second alarm was called because of the size of the building.
Firefighters said residents were safely evacuated, and no injuries were reported.
One resident was displaced because of water damage on the first floor.
The blaze may have been sparked by lithium batteries, firefighters said.
OnScene.TV and City News Service contributed to this article.