Long Beach firefighters are working to mop up the mess and minimize water damage after the sprinkler system went off and doused the fire, fire department spokesman Brian Fisk said.
The fire was out by the time firefighters arrived, but there was a lot of smoke, Fisk said. The structure was not on fire, only contents inside one unit were, but Fisk did not have details on where exactly the fire was inside the unit.
The complex, on Long Beach Boulevard and 21st Street, has 49 affordable apartments for seniors, according to its website.