SAN FRANCISCO—A two-alarm fire broke out on Thursday, January 5 in a 45-unit Forest Knolls condominium in San Francisco, leaving a female resident in critical condition.

The San Francisco Fire Department (SFFD) was notified of the fire just after 8:00 a.m. on the 600 block of Clarendon Avenue. According to the SFFD, the fire took place in the back of a three-story, three-bedroom unit single-family home. Fire officials announced that the incident was under control around 8:37 a.m., though the fire had reached two adjacent units and caused inconsequential damages.

Firefighters rescued one female resident who was transported to the Saint Francisco Memorial Hospital’s burn center with critical injuries, SFFD spokesperson Lt. Jonathan Baxter reported. Upon entering the building, one of the firefighter’s legs fell through the floor, but he was able to get his leg out and did not suffer any injuries, Baxter said.

Donna Boston, who has lived in the building since its opening in 1976, said she called 911 at approximately 8:10 a.m. “We opened the drapes and saw the flames leaping out the back window,” Boston told fire officials.

Judy Clarke, president of the condominiums Home Owners Association, noted that the housing complex is “very quiety and safe,” with the last fire occurring a decade ago.

It has yet to be confirmed how many people the building houses. Officials are still investigating the cause of the fire. There were no reports of any other injuries.