More than 100 firefighters battled a blaze on East 78th Street, the FDNY said. View Full Caption DNAinfo/Trevor Kapp

UPPER EAST SIDE — Three people were injured, one of them critically, in a fire in an Upper East Side apartment building, the FDNY said.

The flames tore through nearly every floor of 314 E. 78th St., near Second Avenue, about 4:45 a.m., according to FDNY officials and witnesses.

"I heard a bunch of people yelling, 'Fire! Fire!' When I got outside, fire trucks were all over the block," said first-floor tenant Chris Lucero, 27.

"Smoke was coming from the third, fifth and sixth floors. It was dark gray and black," Lucero said.

Tenants were frantically trying to escape the flames and smoke as about 106 firefighters tried to bring the blaze under control.

"People were coming down the fire escapes. Firefighters had the ladder up. They were running in and out," Lucero said.

"They dragged a woman out. She was unconscious. They put her on the ground, then on a stretcher."

One person was critically injured in the blaze and taken to New York—Presbyterian Hospital, officials said.

Another person suffered serious injuries but was listed in stable condition at the same hospital, FDNY officials said.

Another civilian and a firefighter were treated for minor injuries at the hospital as well, officials said.

Fire marshals were trying to find out what sparked the blaze Wednesday morning.