Harrowing video showed the doomed Big Apple sightseeing helicopter fall out of the sky into the Hudson River on Thursday as witnesses described the aircraft breaking apart in midair.

The tourist helicopter rapidly dropped into the chilly waters, causing a major splash around 3:20 p.m., video captured by a bystander and obtained by The Post shows.

The tail and rotors of the New York Helicopter appeared to break off before it plunged into the Hudson, killing everyone onboard, according to the footage and multiple witness accounts. 

Warning: Graphic video

One bystander, Charles McSorley, said the rotors just “snapped right off.”

McSorley, 59, was walking from Jersey City into Hoboken when he spotted the helicopter flying nearby.

He then heard a boom and saw the rotors come apart.

“Looked like the propellers came straight off. And I saw it come straight down,” the loading dock manager said.

“And I just started walking fast towards Hoboken because it wasn’t far from the Hoboken train station.”

He said it sounded like the helicopter was “struggling all of a sudden.”

“But you could literally see that the propeller just snapped right off. You can see it snap off, and then it just came straight down.”

The pilot and a family of five Spanish tourists, including three children, aboard the chopper were pulled from the water. Four were pronounced dead at the scene and two succumbed to their injuries at the hospital.

The family was later identified as Agustin Escobar, his wife, Merce Camprubi Montal, 40, and their three children, Augustin, 10, Mercedes, 8, and Victor, 4, according to officials. The pilot was 36-year-old Navy SEAL veteran Sean Johnson, according to reports.

An investigation into what caused the crash is underway.

Nicholas Bahamonde, 34, who had a “bird-eye” view of the disaster, said he saw the helicopter “break apart” in midair.

He was in the middle of a work Zoom call inside his Jersey City apartment when he heard a “loud bang” in the middle of it.

“I look up to the left, and I saw the tail rotor break off of the helicopter, so it was already split in the air, and then the front main part of the helicopter started spiraling into the ocean,” he said.

“I jumped up and I said, ‘Oh my God, there’s a helicopter going down into the Hudson right now.’ And so I got off that and called 911, immediately. But I saw it. I saw it break apart, spiral and crash land into the water like, very clearly.”

Another shocked bystander described the chopper as “slowly falling apart” about 15 feet before it crashed.

“Just walking toward this way from Hoboken and started just hearing something and then you look to the left into the water and you see the plane slowly falling apart,” witness Bruce Wall said.

“It was falling apart probably 15 feet before it actually fell and then the tail whipped off and the propeller fell while it was falling, crashing, the propeller, as you see in the video, the propeller was in the air still propelling while the plane was falling down.”