A Monroe homeowner says he spent three years restoring his historic home, only to watch it be trashed after what he says was an unauthorized party organized through social media.

The gathering happened Saturday night at a mansion on Sapphire Road that was being rented as a short-term vacation property.

Owner Osher Zellig says he believed he was renting the seven-bedroom home to a family for the weekend.

“It is like a nightmare. Just a nightmare,” Zellig told News 12. “It’s an organized scam.”

Neighbors shared videos with News 12 showing a large police response, long lines of parked vehicles and extensive damage inside the home after the party ended.

The videos also show furniture overturned, trash covering the home, debris around the pool, a broken glass panel near the front entrance and a 150-year-old baby grand piano with its legs snapped off.

“That’s so sad because the piano was 150 years old,” Zellig said. “You can’t replace that. To fix it would cost thousands of dollars.”

He says the damage extends well beyond what can be seen.

“The walls, the couches, the beds and everything smells of marijuana,” he said. “There’s a leak in the ceiling, the sewer system was overwhelmed and there was sewer coming out all over the place. The whole basement is flooded with sewer, and the bathrooms are overflowing. The house is a wreck.”

Neighbor Cristina Kiesel says the normally quiet neighborhood was overwhelmed.

“It was complete chaos,” she said. “There were literally hundreds of cars.”

Kiesel says the homeowner told neighbors he thought he was renting the home to a family for the weekend.

“Apparently it’s a big scam where these promoters and DJs rent out a home, put out an Instagram post, invite thousands of people and charge them a lot of money to get in,” she said.

The party was promoted online as the “Biggest Project X Mansion Pool Party in the World.” The promotional flyer advertised DJs, food, drinks, hookah and admission, but did not include the property’s address. Instead, attendees were instructed to message organizers for the location, something the homeowner and neighbors believe prevented authorities from learning about the event beforehand.

According to Zellig, the home was listed on Booking.com as a “Historic Mansion Retreat” recommended for eight guests, with nightly rates starting at about $1,800.

According to Orange County property records, the home sits on 2.1 acres, is valued at $1,004,800 and is owned by 64 Sapphire Rd. LLC, which has a Brooklyn mailing address.

Town Supervisor Maureen Richardson says short-term rentals are permitted in Monroe through a permit process and believes the homeowner was also misled.

“The property owner was also a victim of deception,” Richardson said. “The renter represented that they would comply with all applicable rules and regulations, but instead advertised the party covertly and disclosed the location only to those who had RSVP’d on the night of the event.”

Richardson says the incident also highlights challenges with existing laws governing short-term rentals.

“There’s an incredible amount of gray area in the law, and unfortunately people who trust that justice prevails find out the hard way that these exploits are commonplace,” she said.

Despite the extensive damage to the home, New York State Police told News 12 troopers responded to several noise complaints, determined one additional report to be unfounded and increased patrols in the area for the remainder of the night. Police said none of the incidents they investigated that night were criminal in nature.

Zellig says despite the destruction, one thing stood out.

“This is the most amazing community I’ve ever seen,” he said. “I went around knocking on doors to apologize, and everybody was so nice.”

News 12 has reached out to Booking.com and the social media accounts that promoted the event for comment and is waiting to hear back.