A drunk man fell to his death during a roof party at his Upper East Side apartment Thursday night, according to police.

Max McDonough, 27, was sitting on the ledge of the complex on Second Avenue near 82nd Street with his roommate when he lost his balance and plunged over the side at 11:30 p.m., cops said Friday.

McDonough, who had been dangling his legs over a slanted ledge, fell four stories onto the sidewalk below, police and witnesses said. He was pronounced dead at Lenox Hill Hospital.

“It’s horrible. We’re all really shocked. It’s just disturbing,” said neighbor Jessica Zuo, 22, who lives upstairs from McDonough’s apartment.

She said partygoers were mostly quiet — and she heard nothing suspicious before the tragic fall.

“I just heard a lot of running up and down stairs. I didn’t hear any voices or anything. I didn’t even realize it was a party, I thought it was just one person,” she said.

“It wasn’t until 2 a.m. that I woke up to police buzzing my buzzer for 10 minutes. I let them in and heard them go … check out the roof.”

McDonough had been hosting the party and was intoxicated when he fell, according to police.