A fire tore through the three-story 16th Street building that is home to Taqueria Los Coyotes just after midnight Wednesday night, injuring at least two people and displacing 22 residents.

The two-alarm fire at 1336 16th Street broke out sometime just after midnight, and firefighters responded to the scene at 12:18 a.m. Thursday.

According to SF Fire Department media relations, the fire may have been sparked in "debris" in the alley outside the building, and it was originally reported as a one-alarm fire. A second alarm was ultimately called, and two residents in the apartments upstairs ended up being taken to the hospital to be treated for smoke inhalation.

As the Chronicle reports, the fire damaged 13 units in the building, which are home to 22 people. The Red Cross was on the scene assisting the displaced residents.

As of 1:46 a.m., the SFFD declared the fire under control.

The cause of the fire is still being investigated.

Damage to the popular taqueria on the ground floor was still being assessed Thursday morning, and the restaurant is likely to remain closed at least temporarily.

Update: Mission Local confirms with witnesses and neighbors that the cause was likely debris set aflame in the alley, Wiese Street, left there by the homeless who often camp there. The debris fire appeared to have spread from the alley into the taqueria, and then upstairs.