Two children in Staten Island have died and several more been injured after a house fire was reported to the New York Fire Department. 

The Twitter account for the FDNY said a fire at 1048 Van Duzer St. in Staten Island’s Fox Hill neighborhood was reported at 10:18 a.m. on Dec. 23. When firefighters arrived, they were told there were multiple people trapped on the second floor of the three-story home. 

It’s unclear where the fire started or what led to the blaze, but FDNY chief of fire operations Jack Hodgins said in a news conference that “the entire second floor was engulfed in flames, so much so that the fire was coming down the stairs,” a condition that he described as “very rare.” 

Firefighters were able to suppress the blaze and found the six children in a back room of the second floor. All were unconscious and brought to the street, where they received treatment from the FDNY and EMS services before being brought to a hospital. 

Two of the children died, while two more remain in critical condition. All four are younger than 10 years old, said Laura Kavanagh, commissioner of the FDNY, in a news conference. Police told CBS New York that the two children who died are a boy and a girl aged 5 and 6. All of the children are believed to be related, Kavanagh said. 

Two teenagers who were also in the home are being treated for minor injuries. Authorities believe one is 14 years old, Kavanagh said. One firefighter was also treated for minor injuries, said Kavanagh, and a woman believed to be the children’s mother is being treated at the hospital for shock. She is in stable condition. 

Kavanagh said that officials do not believe there were any adults in the home. The oldest person believed to have been in the residence is the 14-year-old, she said. 

“We do not believe there was anyone other than the teenagers there at the time,” she said. 

Kavanagh and other city officials said the fire was a “terrible tragedy,” especially so close to Christmas Day. 

“It’s an incredible tragedy. We feel it as New Yorkers,” she said. “Our members of course are parents themselves. This is right before Christmas. They do an incredible job, they deal with hard things all the time, but that doesn’t mean that this isn’t tough. It’s tough for all of us.”