The flames broke out around 3:30 a.m. Tuesday at Palos Verdes Inn located on the 1000 block of South Palos Verdes Street.
Los Angeles Fire Department Assistant Chief Daryl Arbuthnott said a total of 150 firefighters responded to the 14-unit transitional housing building and knocked the blaze down in 34 minutes.
"The fire was knocked down in approximately 30 minutes," Arbuthnott said. "Our challenge was treating all the 14 patients that came out, that's what made it very tough."
Several were injured, two hospitalized in critical condition. One sustained 3rd-degree burns; the other suffered from smoke inhalation.
More than a dozen residents were forced to evacuate their rooms after the fire which investigators believe started downstairs extended to the second floor. The fast moving fire melted the smoke alarms and some residents took drastic measures to escape the flames.
According to Arbuthnott, one resident "evacuated by hang jumping by the side of the window."
Resident Monica Naponelli said she saw a few people jumping from a second story window as she raced out of the burning building.
Officials confirmed at least one person was being treated for broken bones as a result of jumping.
Los Angeles Fire Captain Jaime Moore said investigators had sealed off the area following the fire to investigate the scene. Moore said arson is suspected because the fire moved way too quickly.
"Our accelerant section canine is on scene right now, working the scene with his handler, to detect if an accelerant was used in this fire," Moore said.
If the incident is deemed criminal in nature, the fire will spark an arson and homicide investigation.
Resident Tiffany Rogers is five months pregnant and thankful no one was killed in the blaze.
"As soon as I opened the door, there was smoke immediately," Rogers said. "I just grabbed whatever I could and ran out. I couldn't even see through the smoke. I couldn't breathe. I was coughing. It was horrible."
Fourteen people were treated at the scene. Twelve people were transported to the hospital with three people listed in critical condition. Six ambulances were dispatched to the scene. At least one patient was hospitalized with second and third degree burns. An officer also suffered smoke inhalation.
Dozens of people were left displaced and transported on a bus to a shelter set up by the Red Cross.
The building is a transitional home for low-income people. Residents say they believe the fire started in the community kitchen, located on the bottom floor of the building. The cause of the fire has not been determined.
Homicide investigators were on scene Tuesday because of the two patients hospitalized in critical condition.