NYPD video shows Twin Towers on 9/11

Newly released video footage of a bird's-eye view of the Twin Towers after planes plunged into the skyscrapers on Sept. 11, 2001 has surfaced and been posted on the Internet.

The 17-minute video, shot from a New York Police Department helicopter, features plumes of smoke billowing from the World Trade Center as well as the exclamations of shock in the voices of the officers, who shout above the din of the helicopter blades.

They express sadness when they realize the structures have fallen to the ground.

"The whole tower, it's gone," said one officer, reacting to the first collapsing building. "Holy . . . they knocked the whole freaking thing down."

Later in the video, the officers react again.

"All personnel, be advised the North Tower is down," said one officer, seemingly speaking into a radio.

"Holy -- !" screams another.

"Be advised the whole north tower is down," said the officer on the radio.

"That's it," a third officer says. "That's the biggest disaster in the world, probably. Right there."

The video does not seem to show, however, the buildings collapsing.

The footage was obtained through a Freedom of Information Act request by Cryptome, a video-sharing website, said Michael Newman, a spokesman for the National Institute of Standards and Technology, the Maryland-based federal agency that released the video to Cryptome last Thursday.

The NIST has analyzed that video and many others to determine why the skyscrapers fell during an investigation that lasted from 2002 to 2005, Newman said. He said scientists looked at amateur and professional video and also tested samples of steel and other metals to conclude that the towers fell because of three factors.

Those include the impact and damage of the planes crashing into the buildings, the resulting fires from the infusion of jet fuel and the compromised steel supporting the floors. He said the steel was weakened, though not melted, by the fires, which burned for some time, fueled by the office equipment, furniture and paper they engulfed.

"We stand 100 percent behind our findings," Newman said.

A NYPD spokesman said the police department had nothing to do with the release of the video, though he confirmed the footage belonged to the police department.