Dozens of residents were displaced after a fire tore through a Brooklyn Heights apartment building on Monday.

Flames were seen shooting out of the third floor of the building on Pierrepont Street. FDNY crews were able to get the blaze under control within an hour, preventing even more destruction, officials said.

Officials say four people, including one firefighter, were taken to the hospital. The Department of Buildings and fire marshals are working to determine the extent of the damage and the cause of the fire.

Neighbors describe scary scene

Some panicked neighbors said they heard an explosion before seeing smoke, and then watched a woman climb down the fire escape.

That woman, Nisha Datta, said she knew there was only one way out.

"I was on a work call. I heard an explosion, and looked out the window and saw smoke and then the fire alarms started going off," Datta said. "I stupidly went for the door, saw smoke and turned around and ran for the window and went out the fire escape."

Brahim Djokovic said he was walking by when he saw the smoke above, and then ran inside the building to warn people. FDNY Battalion Chief Mark Levens said the fire caused windows to blow out. 

"Once I started to get out with people, thing were popping up, going on the floor. You can hear boom, boom, boom!" Djokovic said, adding when when asked what he was thinking at the time, "I don't care. I just want people to get out."

An exhausted Denise Gamble said she was able to get inside and grab some items, but added her apartment was left in bad shape.

"Water still coming down heavily. The bedroom is pretty much gone. It's not a great start to the new year, but I'm happy my sister was there, my dog, and everyone else in my building are OK. That's what's important," Gamble said.