The fire was reported just before 11:30 p.m. Wednesday night and when firefighters arrived to the five-unit condo building at 123 Knollwood Drive they found flames through the roof, Fire Chief Chris Gray said.
One female resident was safely removed from the building and then taken to Marin General Hospital, he said.
The fire was knocked down sometime before 2 a.m. The fire chief described the fire as "fast-moving," and "extremely intense."
About 50 firefighters responded to the blaze.
Residents from two of the condos have been displaced this morning, Gray said.
Firefighters were still at the scene as of 2:30 a.m. to search for occupants who may still be in the building, Gray said.
The cause of the fire is under investigation, Gray said.