Squatters suspected in San Francisco Mission District blaze

In this file photo, San Francisco firefighters battle a raging blaze on 22nd Street in the Mission District in San Francisco on Wednesday, Jan. 28, 2015. The same building caught fire late Sunday night and fire officials suspect it was started by squatters. less In this file photo, San Francisco firefighters battle a raging blaze on 22nd Street in the Mission District in San Francisco on Wednesday, Jan. 28, 2015. The same building caught fire late Sunday night and fire ... more Photo: Vivian Ho Photo: Vivian Ho Image 1 of / 25 Caption Close Squatters suspected in San Francisco Mission District blaze 1 / 25 Back to Gallery

Squatters living in a burned-out Mission District building are suspected of starting a blaze late Sunday that ripped through the three-story structure, officials said.

The three-alarm fire on Mission Street near 22nd Street broke out just after 11:30 p.m., and the first firefighters on scene were confronted by flames shooting out of the roof and heavy smoke.

The blaze occurred in a building that caught fire in January 2015, killing one person, injuring six others and displacing dozens of residents.

Fire officials said they found evidence that Sunday night’s fire was sparked by homeless people living in the building.

“There shouldn’t have been anyone inside. There shouldn’t have been a heat source,” Fire Department Battalion Chief Kirk Richardson told reporters at the scene.

He said gas and electricity were both cut off following the previous fire.

While no one was in the building when firefighters arrived, Richardson said, it appeared the blaze started on the third floor, apparently by someone cooking.

Investigators said squatters apparently got into the building through a hole cut in a plywood board covering one of the windows.

Firefighters brought the blaze under control by 1 a.m. Monday and remained on scene mopping up the fire in the morning. A neighboring occupied building sustained water damage from the firefight, officials said.

No one was injured in the blaze, which remained under investigation.

Bill Hutchinson is a San Francisco Chronicle staff writer. Email: bhutchinson@sfchronicle.com Twitter: @bill_hutchinson