Police evacuated a New York neighborhood Thursday evening after they discovered a stockpile of hand grenades, munitions, firearms and a tank at the home of a man whose wife had found him dead. Authorities came upon the arsenal of weapons when they went to the home of former Marine and gun enthusiast Jonathan Orser, 41, found dead from a shotgun wound to his chest. His house in Mahopac, N.Y., is in Putnam County, roughly 50 miles north of New York City. The incident happened Tuesday sometime before midnight, when Orser’s wife discovered him, WABC reports.

Police say Orser had a collection of firearms, grenades, low-explosive powders, a large amount of ammunition and a decommissioned tank in his backyard, NBC New York reports. After evacuations in the immediate area, the bomb squad and the Bureau of Alcohol, Tobacco, Firearms and Explosives responded and removed the explosives.

Carmel Police Chief Michael Johnson told lohud.com the tank was legal but many of the weapons and explosives were not. He said police removed “over 100 firearms, rifles and shotguns, 15,000 to 20,000 rounds of ammunition, buckets of black (gun) powder and hand grenades” from the home.

Johnson says the cause of Orser’s death remains unknown but is suspicious. Johnson said Orser might have been cleaning weapons to prepare for a gun show in Rockland County when he shot himself in the chest.

“He cleans the guns and polishes them up (before the show),” Johnson said. “He was found on the floor, surrounded by rifles and shotguns.”

Orser’s friends told police he was a gun enthusiast, survivalist and firearms and safety instructor, Johnson added. The blasting caps found inside the home “could have caused the whole house to go up -- and maybe surrounding houses,” police said.