Fire officials say 17 firefighters were injured Wednesday as they controlled a five-alarm fire in an apartment building in Rego Park, Queens.

The fire broke out around 10:20 a.m. on the sixth floor of 86-16 60th Avenue and lasted more than two hours, according to a New York City Fire Department deputy chief.

Of the more than 150 firefighters who helped put out the blaze, 17 received minor injuries that were mostly heat exhaustion-related. New York Hospital Medical Center received 14 of the injured firefighters, one went to Queens Hospital Center and one went to Cornell with second-degree burns.

One injured firefighter refused medical attention.

New York City Fire Department Deputy Assistant Chief John Sudnik said the firemen were rotated frequently in and out of the fire. Firefighters could be seen sitting and recovering on the streets outside the affected building.

"These last couple days have been a tough stretch for the FDNY. We've had several multiple-alarm fires where firefighters are put under extremely punishing conditions," said Sudnik. "What we try to do with these situations is try to relieve, rotate our personnel as quickly as possible, to try to relieve some of the heat stress placed upon them. These are very, very difficult conditions to work under."

FDNY officials said the fire quickly spread in the area between the ceiling of the top floor apartments and the roof of the building. Residents were forced to quickly leave the building.

"We were all sleeping and we were smelling smoke and stuff. All these firemen were knocking on doors, they were like, 'Get out of the house, get out of the house, there's a big fire.' And they took us out of the building," said one resident.

"Around 10:30 they started ringing, ringing on our bell. I woke up and I smelled fire," said another.

American Red Cross officials said six apartments were destroyed in the fire and as many as 40 others could be affected.

A cooling center is available for residents of the building stranded in the heat.

On Thursday, fire officials determined the blaze was caused by an unattended candle.