Five volunteer fire departments responded to what was described as "a stubborn blaze" on Harbor Watch Court in Noyac Saturday afternoon.
The chief Southampton Town fire marshal, John Rankin, said the flames broke out in the basement and traveled up through the roof, rendering the house uninhabitable.
"There is some significant structural damage to it. There are sections that are not able to be walked on inside the house," he said.
No one was home at the time of the blaze, which was reported at 1:54 p.m. by a passer-by who saw smoke. Sag Harbor Fire Department Chief Steven Miller said that "the house was completely filled with smoke. There was zero visibility."
Nearly 100 firefighters from the East Hampton, Bridgehampton, North Sea, and Southampton Fire Departments joined Sag Harbor in extinguishing the fire, while the Amagansett Fire Department stood ready at Sag Harbor's headquarters to respond to any other calls. There were no injuries reported.
The crews had a hard time locating the "stubborn" fire because "it was in the voids of the house, going up to the second floor, and it was also in the ventilation system," Chief Miller said.
The flames were knocked down in about an hour, and the scene was deemed clear after about two and a half hours. Mr. Rankin said the cause is still under investigation, but added that it is not considered suspicious.
