A team of firefighters was spending the early hours Thursday dealing with any hot spots left in a San Francisco apartment fire that left as many as 60 people homeless, fire officials said.

The five-alarm blaze engulfed three buildings before 150 firefighters, or about half the department's daytime firefighting force, brought it under control after a near three-hour battle, Fire Chief Joanne Hayes-White said Thursday.

Fire investigators will try to determine Friday what sparked the blaze, officials said.

One firefighter to the hospital with a burn to the neck, and a civilian was treated for mild smoke inhalation, Hayes-White said. A second firefighter was given oxygen at the scene.

"It was a challenging fire to fight, but given the time of day, it was actually helpful because most people were out of their dwellings," the chief said.

Hayes-White said the fire started in one of the neighborhood's trademark three-story Victorian homes and spread to a nearby apartment building and a single-family home. A total of 32 dwellings were destroyed.

As the fire burned during the afternoon, a pillar of thick smoke rose over the residential neighborhood. Authorities closed several blocks of streets, causing massive traffic jams in the area.

The fire spread easily due to brisk winds and because the building where the fire started was made of wood and directly attached to other buildings, Hayes-White said.

The Red Cross was caring for residents displaced by the fire.