The two-alarm fire, reported at 1:28 a.m. Saturday in the 900 block of Montgomery Street near Pacific Street, injured four people and caused nearly $1.5 million in damage, San Francisco fire Lt. Mindy Talmadge said.
Firefighters controlled the blaze at 4:37 a.m., Talmadge said. A firefighter and three residents suffered injuries in the fire and were taken to a local hospital, she said.
The firefighter has since been released from the hospital, but Talmadge did not know the conditions of the other three victims.
The cause of the fire, which displaced 48 adults and six children from several different units, had not been determined as of today, she said.
The building sustained about $1.15 million in damage to its structure and about $300,000 to contents inside, Talmadge said.
She did not know when the residents would be able to return to the building.
"It could be a while," she said.
In the hours after the blaze, the Bay Area chapter of the American Red Cross opened a shelter for displaced residents at the Eugene Friend Recreation Center at 270 Sixth St., where 28 people were still staying Monday night, Red Cross spokeswoman Caitlin Cobb said.
Displaced residents consisted of about a dozen families, including a few elderly residents. Some of them were able to find places to stay with family and friends, Cobb said.
The shelter was scheduled to close today at noon, and the remaining residents will be placed in nearby hotels.
"Generally we only keep the shelter open for a few days," Cobb said.
The remaining residents will be placed in nearby hotels for up to six days, Cobb said.
The cost of the hotel stays will be split evenly between the Red Cross and the San Francisco Human Services Agency, Cobb said.
The Red Cross will continue to assist any residents who are still displaced after six days.