NEW YORK (AP) -- Federal officials investigating the destruction of the World Trade Center said Sunday they hope a newly surfaced videotape showing both hijacked planes hitting the towers will shed light on why the north tower collapsed.
``You could use it to determine the speed of the plane as it approached the building,'' said Michael Newman, a spokesman for the National Institute of Standards and Technology, the agency investigating the collapse of the 110-story towers. ``That gives us information that we can use to determine a number of different factors.''
The tape's existence was reported by The New York Times on Sunday, two years after the terrorist attack felled the twin towers on Sept. 11, 2001.
It is the only videotape known to have captured images of both planes hitting the trade center. And while numerous videos and photos have provided details on the high-speed impact into the south tower, it is only the second showing the first strike, into the north tower.
The tape was shot by a Czech immigrant construction worker, whose young son at one point came close to accidentally erasing it.
Newman said NIST is trying to obtain a copy of the hourlong tape, parts of which aired on ABC Sunday.
``Any visual documentation we can get of the events of 9-11 is valuable,'' Newman said.
Walter Karling, a freelance photographer who is acting as an agent for the man who shot the footage, Pavel Hlava, said Sunday he could not comment on whether the tape would be turned over to investigators.
NIST investigators have compiled a database of more than 5,600 photographs and 4,600 video clips shot that morning by both professionals and amateurs.
The only other known footage of the first plane striking the north tower came from a French film crew that was making a documentary about a firefighter.
Just as hijackers crashed American Airlines Flight 11 into the north tower, Hlava was shooting video out the window of a vehicle approaching the Brooklyn-Battery Tunnel en route to lower Manhattan. His boss was driving.
Hlava told the Times he did not see the first plane on his viewfinder, although the tape shows a whitish object hitting the tower, followed by debris spurting from the tower's side.
While passing through the tunnel, Hlava and his companions heard a radio report that a small private plane had hit the World Trade Center, which was straight ahead outside the tunnel. When they emerged, the north tower loomed over them, its upper floors engulfed in flames.
As Hlava continued filming, the second airliner shrieked behind him and into the south tower.
Later, after the group crossed the Brooklyn Bridge back into Brooklyn, he focused on the buildings again as the south tower collapsed.
Hlava and his brother, Josef, unsuccessfully tried to sell the tape in New York and in the Czech Republic.
``There was no interest,'' said David Melichar, a fellow Czech immigrant acting as a translator for Hlava, who does not speak English.
A friend of Hlava's wife obtained a copy of the tape and traded it to pay off a bar tab. Another woman learned of that copy and informed Karling, who took the tape to the Times.
The Times and ABC both said they did not pay for the tape. Karling refused to comment.
