SAN FRANCISCO (KGO) -- San Francisco fire crews responded to a large fire in the NoPa neighborhood early Monday morning.
The 3-alarm fire was at Grove Street and Masonic Avenue, where multiple buildings were evacuated.
Neighbors woke up to loud sirens and flames shooting out of both the second and third floors of a home just before 3:30 a.m.
"The flames were coming out of both stories at the time," Nathan Hall-Snyder, a neighbor said.
The fire was so powerful it caused a partial floor collapse of the home and a desperate escape for two people living inside.
"One person jumped out of the fire building, unknown whether it was the second or third floor at this time moderate injuries and another person from that fire building as well with minor injuries escorted out of the building," Lt. Mariano Elias, a spokesperson for the San Francisco Fire Department said.
Hall-Snyder, a neighbor two doors down, says he had less than a minute to grab what he could and evacuate with his roommate.
"We had previously lived in a wildfire zone...so we actually had all of our go-bags ready to go so I grabbed what I needed and left very quickly," Hall-Snyder said.
Fire officials say the home where the fire started is a total loss.
Two neighboring homes are damaged and seven total people are displaced.
Investigators say it appears some construction work was happening at the home that caught fire.
It's unclear if it sparked the fire, but it could have fueled the fast-spreading flames.
"The studs are exposed, and when a fire happens in something like that, a fire travels very rapidly, more so than when you have installation and sheetrock on the walls so that may have caused the amount of flames to be present upon our arrival," Elias said.
The Red Cross is assisting the seven people displaced right now.
Fire officials say the northbound lanes of Masonic from Grove to Hayes Street will likely remain closed for most of the day while investigators work to find out what caused this fire.
Officials say that all other evacuees are allowed to return to their homes.
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