NEW ROCHELLE, N.Y. (CBSNewYork) – A historic mansion in Westchester County went up in flames Monday night and firefighters say someone may have set the fire intentionally.

The Wildcliff mansion in New Rochelle was badly damaged by fire Monday. CBS2’s Reena Roy reports that smoke could still be seen coming out of the wreckage hours after the blaze.

Neighbors watched in shock as one of the city’s most historic landmarks began burning and then partially collapsed around 4 p.m.

“I was shocked…It’s a historic building it’s really a shame” George Morris said.

1126mansion Historic New Rochelle Mansion Burns Down In Suspicious Fire

Wildcliff mansion in New Rochelle bursts into flames Monday night. (Credit: CBS2)

Officials say Monday’s messy weather made things especially tough, with firefighters facing muddy conditions.

“It was fully involved from the beginning… The rain didn’t help,” New Rochelle Fire Chief Andy Sandor said.

The gothic-style structure was built in 1855 and was gifted to the city of New Rochelle in the 1940s. It was used for city offices and non-profit groups, but was unoccupied in recent years.

“It wasn’t put to good to use lately that’s the way things happen with abandoned buildings, people take advantage of it,” Morris added.

The Wildcliff mansion was listed on the National Register of Historical Places in 2002. Now, officials say it will have to be razed after the investigation into what caused the fire.

New Rochelle mayor Noam Bramson said in a statement that he was “deeply saddened by the loss.”

The fire chief says the gas has been shut off in the mansion for years. They added that the blaze does appear to be suspicious.