CARMEL, N.Y. (CBSNewYork) — A Larchmont police captain, his wife and two daughters who were killed when their Carmel home burst into flames died of smoke inhalation and carbon monoxide, a coroner said Wednesday.

The Putnam County coroner said based on the preliminary autopsy results, it likely means Larchmont Police Capt. Thomas Sullivan, his wife, Donna, and their two daughters, 17-year-old Meghan and 15-year-old Mairead, died before they were burned.

WCBS 880’s Sean Adams reports

Officials were still investigating what sparked the deadly blaze, but have now determined that it started at the front of the Sullivan’s home early Tuesday morning.

“The origin has been determined to be on north side, front of residence,” said Carmel Police Chief Michael Johnson. “Cause, undetermined at this time pending samples. Samples will be expedited to state police crime lab in Albany.”

The fire scene will remain secure until all suspicion is ruled out. Police are treating it as a crime scene until they can determine an exact cause, which could take several weeks.

Investigators said the Sullivan home had eight wired smoke detectors, but it’s unclear if they were working. The home was made of newer, fast-burning materials and it quickly collapsed.

“I know Tom. He was a button-up guy. I know those smoke detectors were working,” Putnam County Executive Mary Ellen Odell told CBS 2’s Lou Young.

The fire was so intense, it melted the siding of the house next door and off nearby cars and burned the victims’ bodies beyond recognition, authorities said.

The remains of the Sullivan family house, destroyed by fire - Carmel, NY - May 2, 2012 (credit: Sean Adams / WCBS 880)

The remains of the Sullivan family house, destroyed by fire – Carmel, NY – May 2, 2012 (credit: Sean Adams/WCBS 880)

Thomas Sullivan’s body was found on the rear deck of the home. The Larchmont police captain had apparently landed there after jumping from the second floor, officials said.

The family’s four Yorkshire terriers also died.

The only one to survive was the Sullivan’s son, 20-year-old Tommy Jr., who escaped after hearing his father alert the family to the flames.

“His preliminary account was that his father was yelling, alerted him that there was a fire in the house and he crawled downstairs and was able to get out through the garage,” Johnson said.

Police said they were re-interviewing Tommy Jr. on Wednesday, a routine part of the investigation, CBS 2’s Young reported.

Meanwhile, classmates of two teenage girls at Carmel High School, where Meaghan was a senior and Mairead a freshman, are grieving. Mahy wore purple on Wednesday as a sign of solidarity, Young reported.

“I think that the second day might be a little more difficult than the first,” said principal Kevin Carroll. “I think yesterday was just a shock to everybody and people don’t know how to react.”

Liz Alfieri was a close friend of the Sullivans and called them devoted parents.

“Any of us needed anything at anytime, a ride, a helping hand, Tommy was always the first one there,” said Alfieri. “To our community, this is a tremendous loss.”

Sullivan Family (Facebook)

“A man full of integrity, honesty, family man, very dedicated to both his job and his family,” said Larchmont Police Chief John Poleway. “He certainly is going to be missed.”

Heartbroken friends are now focusing on the well-being of Tommy Jr., who was treated at Danbury Hospital and is now staying with his grandparents in Dutchess County.

Police officers from multiple jurisdictions were helping arrange a full inspector’s funeral for the fallen police captain, his wife and two daughters in town on Saturday, at St. James the Apostle Church in Carmel, Young reported.

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