Five people including three firefighters were hurt in a fire early Monday morning in Williamsburg, Brooklyn. 

The fire broke out just before 2 a.m. at a home on Humboldt Street near Richardson Street. Firefighters were on the scene in less than three and a half minutes, the FDNY said. All three floors of the building at 494 Humboldt Street were burning when firefighters arrived. 

The building is made of wood, and isn't fireproof. 

"It's very labor-intensive. The fire gets into the voids of these very old structures, so we have open up the walls, the ceilings, the floors manually," FDNY Chief of Operations Kevin Woods. 

The fire quickly spread to two neighboring buildings, and grew to four alarms. 

Residents say everything they own was destroyed.   

"We were in bed. Our neighbor came ringing our door frantically, he woke us up. We smelled smoke, popped my head outside, flames shooting out of his building," one resident said. "Everything's gone."

That resident was grateful that his family was OK, however. 

Both 494 and 496 Humboldt Street were issued full vacate orders due to fire damage. The Red Cross said it's assisting six adults after the fire. 

The cause of the fire remains under investigation.