The Putnam Valley Fire Department responded to the blaze at a home on Pine Street and had it under control in about 45 minutes, according to Putnam Valley Fire Chief Shawn Keeler.
The fire has been ruled accidental by fire inspectors, he said.
About 14 people were living in the house, but only three were home when the fire broke out, Keeler said.
They were all able to escape safely, and no firefighters were injured battling the blaze, the chief said.
The fire started in an attached storage room and spread through the walls and into the attic, Keeler said.
Smoke and water damage has made the house unlivable, and the tenants are being helped by the Red Cross, Keeler said.
The Fire Department also pitched in by providing a meal for the displaced folks Monday night.
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