Suffolk County police's Arson Squad is investigating a fire that overwhelmed a home under construction Tuesday night in Water Mill.
A police spokeswoman said Wednesday the fire on Seven Ponds Road was under investigation after several East End fire departments had worked to control the blaze.
Second Assistant Chief Chris Brenner of the Southampton Fire Department said the fire started at about 7:12 p.m. and described it as "massive."
"You can see the smoke as far away as Medford," about 35 miles away, Brenner said Tuesday.
At least 100 firefighters battled the blaze, he said.
The home was vacant and there were no injuries reported as of 8:30 p.m. Tuesday, when firefighters were working to douse remaining hot spots, Brenner said.