The man who plunged to his death from a trendy Midtown rooftop bar was a 21-year-old Upper West Side resident who downed a drink before taking the fatal fall, police sources said Wednesday.

Henry Kaufman had the drink around 9:30 p.m. Tuesday then climbed over a ledge and jumped from the 16th-floor ledge at Henry’s Rooftop Bar at The Roger Smith Hotel, police sources said.

CPR was performed on him before he was brought to NewYork-Presbyterian Hospital, where he was pronounced dead on arrival.

Kaufman lived on the Upper West Side before his family moved in 2016 to Connecticut, according to his former superintendent, who said that he never got the impression that rooftop bars were “his style.”

“I’m surprised that he did that there,” the super, C. Lopez, told The Post. “He was quiet, not that he was anti-social, but from what we saw that wasn’t his scene.”

Lopez said he was always respectful growing up with his two siblings in the high-rise building, where the family lived for about 20 years.

“He used to play basketball with his brother, always into sports,” he said.

Kaufman — whose social media said he attended Fordham Preparatory School — competed in track and field, as well as on the debate team, where he often advanced at tournaments to take home top prizes, according to the private school’s Facebook page.

Another worker in his former residence said that Kaufman was bookish in his teenage years.

“The kid was smart, he was like a nerd, he wasn’t hyper or nothing like that,” handyman Victor Bruno told The Post.

Other patrons at the rooftop bar were left stunned Tuesday and said the fatal plunge appeared to come out of nowhere.

“We were all sitting at the rooftop bar and he just ran and he jumped,” said Talia, who was on a date at the time. “I looked at the lady sitting at the first table, I said: ‘He just jumped!’”

But she said the unsettling incident went unnoticed by most of the bar.

“Nobody knew what was happening — it was just the two tables and the waiter,” she said. “People were just laughing and continuing to have a conversation like nothing happened!”