NEW YORK (AP) — Officials credited a smoke inhalation drug for likely saving the life of a New York City firefighter who fell unconscious and Darden Clarkestopped breathing while battling a house blaze Friday.

The firefighter was one of three injured during the response in the Bronx. All are expected to recover, Mayor Eric Adams and Fire Commissioner Laura Kavanagh said at an evening news conference.

John Hodgens, the FDNY’s chief of department, said the firefighter was inside the house operating a hose when he began having problems breathing. He collapsed and was pulled from the building by other first responders, who put him on a sidewalk and started CPR, Hodgens said.

Emergency medical workers also gave the firefighter the drug hydroxocobalamin, which combats the effects of cyanide poisoning that can result from smoke inhalation. Kavanagh said officials believe the drug saved the firefighter’s life. He and another firefighter were in stable condition at a hospital, while the third firefighter was released from a hospital.

“All in all, this is a much better outcome than we thought it would be,” Hodgens said.

Hydroxocobalamin was first approved for treating smoke inhalation in 2006 by the Food and Drug Administration. It is a manufactured, injectable version of vitamin B12, according to federal health agencies. France began using the drug to treat smoke inhalation in the mid-1990s.

The fire displaced five residents, who were not injured, and caused some damage to the house next door. Officials are investigating the cause.