Three New York City firefighters were critically injured Friday in what the commissioner said was a “very close call” as wind-swept flames tore through a Staten Island duplex. They are alert and expected to survive, officials said.

Firefighters rescued a lieutenant from the second floor after he transmitted a mayday signal during a search for occupants in one of the homes, in the borough’s Arden Heights neighborhood, Chief of Department John Hodgens said.

A nozzle man involved in the rescue was hit in the head by falling plaster, dislodging his mask and forcing him to breathe in heavy smoke, Hodgens said.

Another firefighter jumped from a second-floor balcony after getting trapped by fire, Hodgens said.

All three firefighters were taken to Staten Island University Hospital, where they were listed in stable but critical condition.

Fire Commissioner Laura Kavanagh said at a hospital news conference that the injured firefighters are awake, alert and even cracking jokes, but that they continue to be monitored and treated for a variety of injuries.

“I cannot emphasize enough that this was a very close call for the FDNY,” Kavanagh said. “We could have lost three members today.”

Nineteen other firefighters sustained minor injuries, Kavanagh said. No residents were hurt.

The blaze started around 1:30 p.m. in a space between additions in the back of each home and quickly spread to the attached buildings, Hodgens said.

Firefighters searching the homes were trapped when heavy winds broke through the windows, which intensified the fire and blew flames toward them, Hodgens said.

Bystander video showed heavy flames and thick. black smoke coming from the home. One of the extensions collapsed as firefighters battled the blaze. The fire was under control by around 2:46 p.m. The cause is under investigation, Hodgens said.

“With the amount of fire upon arrival and the wind condition, it was a difficult fire,” Hodgens said. “It was a difficult fire that required us to really work very hard.”

The president of the firefighters union said the closest firehouse was closed Friday because of scheduled firefighter medical exams, possibly delaying the fire department’s response.

Another engine company was involved in an accident on the way to the scene, Uniformed Firefighters Association President Andrew Ansbro said.

“Had Engine 167 not been closed, more firefighters would have arrived faster and put water on the fire that much quicker, resulting in less damage and possibly sparing some firefighters injuries,” Ansbro said.

(AP)