One person is dead and at least 17 others are injured after a fire broke out inside of a residential building in Harlem Friday, fire officials said. 

The fire started just before 2:15 p.m. on the third floor of a six-story building on St. Nicholas Place between West 148th Street and West 150th Street, the FDNY said. 

A total of 18 people were treated by EMS personnel, FDNY Chief of EMS Operations Michael Fields said at a news briefing.

Police said 12 of those people were transported to Harlem Hospital. One of those people was pronounced dead at the hospital, according to police. Three others remain in critical condition, and eight others are in stable condition, police said. 

Police said the person who died was a 27-year-old man who was found trapped inside the building and suffered smoke inhalation. 

Another person who is currently in critical condition was transported to Mount Sinai Morningside Hospital, the NYPD said.

Two firefighters and three police officers were also taken to area hospitals and are expected to recover, according to police. 

FDNY Chief of Department John Hodgens said at the briefing that rescuing patients from the fire was a “challenge,” as there were “heavy smoke conditions” in the upper floors of the building.   

According to Hodgens, FDNY personnel used a procedure called a “life-saving rope evolution” to rescue people who were trapped and hanging outside of windows. In the evolution, firefighters attach themselves to a rope, and another firefighter goes off the side of a building to a window and grabs a person who is trapped by a fire, according to Hodgens. Hodgens said although the procedure is normally done once or twice a year, it was performed three times in this particular fire.

Fire marshals are investigating the cause of the fire, according to officials.

The Department of Buildings issued a full vacate order of the building due to damage caused by the fire.

"Upon our arrival to the scene, our inspectors observed significant fire damage in the building, including charred beams, damaged partition walls, damaged windows, and holes in the roof,” said DOB spokesperson Andrew Rudansky.

The American Red Cross said it has opened a reception center at PS/IS 210, where impacted families can register for emergency assistance, and get blankets and hot meals. The agency added that it will also remain on scene to support impacted families, such as Astou Fall and her family.

Fall said she’s grateful her husband was able to get out with only minor injuries.

“I just hope everything works out and everyone is safe. That’s my only prayer," she said.