A five-alarm fire in an apartment building on San Francisco's waterfront sent flames 40 feet in the air, according to the San Francisco Chronicle.
One firefighter suffered minor burns, but there were no other reports of injuries.
The structure is a 172-unit apartment building in Mission Bay under construction near AT&T Park, according to the local CBS TV affiliate.
The two top floors crashed down as the fire weakened the structure, according to SFGate.com, and billows of smoke could be seen from miles away.
"The building is likely to come down," Fire Chief Joanne Hayes-White told the Gate. "It will collapse. The more it burns, the more water we put on it, the more likely it is to fail."
Dramatic photos of the fire quickly surfaced on Twitter.
Looks like a huge fire in one of the under construction buildings at Mission Bay pic.twitter.com/oukKuVetZR— Michael Bauer (@michaelbauer1) March 12, 2014