Ramapo police responding to a 10:27 a.m. call on Slinn Avenue found "a large volume of fire going up the northwest corner of the house," Sgt. Kenneth Joyce said.
Spring Valley firefighters battled the blaze with assistance from their Hillcrest and Nanuet colleagues.
"All the residents got out safely and have made arrangements to stay with family for the time being," Joyce said.
Ramapo detectives, a Rockland County BCI team and Ramapo fire inspectors were looking into the cause of the blaze, he said.
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