A house fire that killed a suburban New York police captain and most of his family wasn't criminal in nature, an official familiar with the investigation said Wednesday.

The May 1 fire in Carmel killed Larchmont Capt. Thomas Sullivan Sr.; his wife, Donna; and their daughters Meaghan, 18, and Mairead, 13.

A son, Thomas Sullivan Jr., 20, survived. He told police he escaped after hearing his father shout that the house was on fire.

The official spoke anonymously to The Associated Press because results of the investigation haven't been made public. Carmel police Chief Michael Johnson said Wednesday that he would release an update on the findings of the investigation at a news conference Thursday.

The official said Johnson will announce the exact cause of the fire and had already declared the blaze "not suspicious."

A call to the Putnam County district attorney's office wasn't immediately returned.

Johnson said last month that Thomas Sullivan Jr. was questioned for 3 1/2 hours the day after the fire and "was able to provide additional details of what occurred that night."

The house, in a quiet neighborhood of large homes about 60 miles north of New York City, was quickly consumed in a fireball. The blaze melted the siding of two nearby homes and plastic and paint on cars. Police said it started near the front of the house.

A coroner said the victims died from breathing smoke and carbon monoxide.

Police sent samples from the scene to a state crime lab and interviewed neighbors and emergency responders.

About 1,000 people attended the Sullivans' funeral, including a long line of uniformed officers who saluted the procession.