Crews have extinguished a four-alarm fire at a multiple-story apartment building along Washington Street in San Francisco.

The San Francisco Fire Department responded to Washington and Larkin streets just before 6 p.m., finding fire on the first and second floors. They also saw fire coming through the roof.

The fire was declared a two-alarm fire, before being upgraded to a four-alarm fire.

Crews said the fire extended throughout the building and that all three floors had burned. The buildings next to the fire have also sustained damage.

By 8:30 p.m., crews said the fire was extinguished but would remain at the scene for several hours to extinguish hot spots and mop up operations.

Three people have been treated on scene, Chief Dean Crispen said. Crispen said he saw a woman in a wheelchair be pulled out. He said crews helped two people walk down the stairs.

One person was taken to the hospital.

About 120 firefighters were at the scene. 

At this time, it's not known how many people will be displaced and what caused the fire.