The blaze broke out around 6:18 a.m. Wednesday at the Novo-Diveevo convent located at 100 Smith Road, Clarkstown police Det. Peter Walker said.
Officials were altered to the fire by a woman in the cottage who smelled smoke and called 911.
No one was injured, Walker said.
Fire departments on scene included the lead Spring Valley, and Nanuet, Hillcrest, and West Haverstraw.
The cause of the fire is under investigation.
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