One of every New Yorker’s worst nightmares played out Thursday morning when a Kips Bay man was crushed to death by an elevator in his luxury high-rise as his horrified neighbors looked on, authorities said.

Sam Waisbren, 30, clawed desperately to escape the packed lift as it plunged from the lobby into the darkness of the shaft below, but he was crushed between the elevator car and the shaft wall, according to officials.

“The guy literally was trying to climb out onto the floor while the elevator was still [moving down],” said a building worker, who witnessed the death and asked not to be identified. “It’s awful.”

The horrific scene, which played out at the 23-story Manhattan Promenade tower on Third Avenue near East 25th Street just after 8:15 a.m., was captured on building surveillance footage exclusively obtained by The Post.

As one woman stands waiting, the elevator door opens into the lobby and a man wearing a backpack emerges, then wheels around as the lift gives way and Waisbren and five others go rocketing downward, the clip shows.

Waisbren instinctively shot out his right hand to grab the frame of the elevator door and tried to plant his right leg onto a sliver of lobby floor, but was immediately overpowered.

“His initial reaction was to put his arm out . . . so he could get off,” the building worker said. “At that point, the elevator took him down. Jumping out [of] the car while it’s still moving, you just don’t want to do it.”

First responders pronounced Waisbren dead at the scene.

“He was a wonderful young man,” said his father, Charles Waisbren, who added that his son had moved from their family home outside Milwaukee to settle down in the Big Apple, where he worked in software sales. “He had millions of friends out in New York. He was loved by everybody.

“We are absolutely devastated.”

Firefighters raced to rescue the five people who remained trapped and traumatized inside the cramped metal cage.

“Some people were still left down in the car after it moved down in the basement,” said FDNY Deputy Chief Anthony Arpaia. “The FDNY had to work really hard to get the car moved.”

With the others free and clear, the chaos gave way to questions.

While the city’s Department of Buildings — on scene investigating the incident late into Thursday — said the killer elevator had not been the subject of any formal complaints over the past decade, the building’s other lift was shut down over safety issues months ago.

“Door zone restrictor has been tampered with,” reads a public report on that violation, formally inspected on May 29. “This is a safety device to ensure elevator passengers’ safety.”

The DOB issued a cease-use order after the inspection, but the building’s management company, ATA Enterprises, satisfied city inspectors and got the order lifted by May 31.

That elevator had been taken out of service Wednesday night because it kept getting stuck, residents said Thursday.

ATA did not respond to multiple requests for comment.

A veteran elevator-safety expert said Thursday’s tragedy also smacked of human error.

Kevin Doherty, a Rockland County-based consultant who viewed the video several times on Thursday and has testified in hundreds of elevator-accident cases, said similar incidents he has investigated involved “somebody manipulating the elevator safety circuit in the elevator machine room” to troubleshoot the elevator.

“Elevator controllers/computers are designed to prevent motion of the elevator when either the inside car door or the outside hoistway door is in the open position,” he said.

“In order for this event to occur, you would have to have a number of mechanical and electrical failures occur simultaneously, barring human intervention.”

The odds of that happening are “almost incalculable,” he said.

Doherty — who investigated a 2011 elevator accident that killed ad exec Suzanne Hart in a Midtown office building, which was blamed on a bypassed safety circuit — also noted that Thursday’s deadly incident could easily have turned out differently.

“The first guy was lucky to get out,” he said. “He has no idea how lucky he is.”

Residents said they had grown used to the balky elevators at the Manhattan Promenade, where monthly rent for a one-bedroom is $3,695, according to StreetEasy.com.

“They always jump between floors,” said one resident who declined to be identified, likening the rides to something out of a horror movie. “It’s like that Halloween-night thing when you’re in that scary elevator that hops up and down. It’s really bad.”

Added Dayna Sargen, 39: “It’s sadly not shocking and sad that it wasn’t addressed sooner. A life could have been saved. It shouldn’t have to take someone dying to have a management company realize there’s an issue with our elevators.”

Waisbren’s father agreed.

“The elevator was always in disarray, and they’re paying a gazillion dollars in rent every month,” he said. “[The] least the building could do is provide safety.”

Additional reporting by Larry Celona and Natalie Musumeci