The fire burned through the home on Wyndham Lane in Carmel just after 2:00 a.m.
The house collapsed as flames quickly tore through the structure.
Larchmont police Captain Thomas Sullivan, his wife Donna and their two teenage daughters were unable to get out before the collapse.
"His son was the only one who made it out, in a family of five," Larchmont police Sergeant Ronald Knudson told the Journal News. "His wife and two daughters perished with Tommy. His son is in the hospital and we don't know his status."
Sullivan's 20-year-old son, the sole-surviving member of the family, escaped by crawling down the stairs and out of the garage after being woken up by his father screaming about the fire. He was treated and released for smoke inhalation at Danbury Hospital and is staying with relatives at this time.
The two girls, Mairead and Meaghan, were students at Carmel High School. Mairead was a freshman and Meaghan a senior.
"The school community is devastated," district superintendent James Ryan said. "We are working together in this very difficult time to offer supports to students and staff."
The blaze was so intense that it melted the siding of two nearby homes and prevented firefighters from entering, said Carmel Police Chief Michael Johnson.
Firefighters from Lake Carmel, Mahopac and Brewster assisted in bringing the fire under control around 5:00 a.m.
Sullivan is a 15-veteran of the Larchmont police department. He had previously served six to seven years with the New York Police Department in the Bronx.
"He was a dedicated law enforcement individual, an extremely great family man," Knudson said. "His life revolved around his family and his job."
Police brought dogs to the scene to help search for victims.
Authorities say there were eight wired smoke detectors in the house, though it is unclear if they were working. Whether the fire was suspicious or not is still being investigated.
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