A 21-year-old man jumped 16 floors to his death from a swanky Midtown rooftop bar Tuesday night, police said.

The victim was pronounced dead at the scene after the 9:30 p.m. leap from Henry’s Rooftop Bar atop the The Roger Smith Hotel at Lexington Avenue and East 48th Street, cops said.

The apparent suicide left some rooftop witnesses stunned.

“We were all sitting at the rooftop bar and he just ran and he jumped,” recalled Talita, a 48-year-old woman who was on a date at the time.

“I looked at the lady sitting at the first table, I said: ‘He just jumped!’”

Talita, who works for the United Nations, said the outside area was fairly empty, with just a few tables and a server, when he jumped.

The other patrons, she said, continued on with their business.

“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!”

The man’s identity was not released Tuesday night.