OCEANSIDE–Multiple families were displaced after a structure fire tore through their Oceanside apartment complex on Saturday afternoon, the Oceanside Fire Department said.

Shortly after 2 p.m., the Oceanside Fire Department was dispatched to a report of a three alarm structure fire at 1409 Division Street at 2:09 p.m. Saturday afternoon.

Oceanside firefighters arrived on scene and found heavy fire from two buildings with a third beginning to burn. Fire departments from Carlsbad, Vista, Encinitas, North County Fire Protection District, and San Marcos were called for assistance.

First responders treated multiple burn injury victims, two of whom were assessed and transported to UCSD Hospital Burn Center. A third was assessed and released at the scene.

The fire originated in a single family residence with an additional two dwelling units built as additions.The fire was driven by wind to ignite the nearby two story apartment building with six dwellings. A total of three buildings and nine dwelling units were damaged by fire.

Full fire control took an extended period of time due to the extent of the blaze, its location in the attic of the two main dwellings, and large amounts of combustibles inside and outside of the buildings.

Investigators performed an initial evaluation of the scene and will continue to investigate. Official cause and origin of the fire are yet to be determined.

The Red Cross and Oceanside Neighborhood Services Department assisted the fire victims with lodging and emergency needs.

One firefighter suffered a minor injury not requiring treatment at a medical facility.