SF firefighters respond to 1-alarm blaze in Mission District

San Francisco firefighters made short work of a one-alarm fire in the Mission District Monday night.

The incident began at 8:30 p.m. at an address in the 2500 block of Mission Street at 22nd Street, according to firefighters.

The structure has been deteriorating since a fatal four-alarm fire in January 2015, and firefighters say they're being safe due to the condition of the building. 

Officials say it appears to be squatters that caused the fire. They were also blamed for another small fire last month.