Witnesses say it was deliberately set and investigators call it suspicious. Two firefighters were slightly injured.
Firefighters were called to the scene around 6:15 p.m. The fire started in a house on Rondel, a small alley off 16th Street between Valencia and Mission. More than ten engines responded as crews swarmed the house and storefronts on Valencia to keep the blaze from spreading.
"We've evacuated every building. PG&;ampE has shut down the gas to all the buildings. Now, we're working, because we did have live wires down in the alley,about PG&;ampE getting in there and making sure those wires were turned off in the back," Deputy Chief Pat Gardner explained.
The fire paralyzed business and restaurant traffic along Valencia. Onlookers lined the block and rooftops.
"I saw a bed on fire and I called the fire department," Chad Archer told ABC7.
Archer lives in the basement of the house where the fire started. He said he saw a mattress was on fire and all the burners on a gas stove were turned on.
"There's a lot of books in the house, so it went up quick," he said. "I believe someone set the fire on purpose."
He claims a tenant was evicted Friday. Others who live in the house were panicked.
"The neighbor who lives downstairs called me while I was at the cafe and told me my house was on fire. I came home as fast as possible. He said he got my dog out," resident Joe Miller recalled. "I've got tons of stuff in there, amplifiers, guitars, computers."
The fire spread to a second building. Within an hour, firefighters had it under control, but there were injuries.
"We had two firefighters hurt. One, we think it's exhaustion, which we hope. The second, because of lacerations. They were both transported to the hospital, minor injuries and they're both OK," Gardner reported.
43 people total were displaced from their homes and apartments. The Red Cross is offering assistance.