Seattle police cataloged the video footage captured by nearby businesses, pulled out the relevant bits and supplied copies to NTSB investigators, the NTSB's Dennis Hogenson said.
A number of nearby businesses, including the Space Needle and a McDonald's restaurant, had some sort of video, and some of that showed the KOMO-TV news helicopter taking off Tuesday, he said. It plummeted to the street and burst into flames, setting three vehicles ablaze and spewing burning fuel down the street.
Investigators also took samples of the railing around the KOMO rooftop helipad. Hogenson said the samples will be sent to a materials lab in Washington, D.C. for analysis. Investigators aren't looking for anything specific, they're just "seeing some things they don't understand," he said.
At a secure hangar in Auburn, south of Seattle, the work of reconstructing the helicopter from its charred wreckage continues.
The agency continues combing through pilot and maintenance and company records associated with the flight, Hogenson said. Investigators are focusing on the helicopter's engine, the airframe, the pilot and the environment.
A preliminary report could be released by Monday. A final report could take as long as a year.
Witnesses reported hearing unusual noises coming from the aircraft as it lifted off from the helipad on top of Fisher Plaza, KOMO's headquarters, after refueling. Witnesses also reported seeing the helicopter rotate before it crashed.
Killed were former KOMO veteran photographer Bill Strothman, 62, and pilot Gary Pfitzner, 59. Both men were working for Helicopters Inc., which owned the Eurocopter AS350 helicopter. The aircraft was leased jointly by KOMO and KING-TV.
Richard Newman, 38, of Seattle, remained in serious condition at Harborview Medical Center. He was burned when the helicopter crashed on his car. The hospital said Newman will need surgery for burns that covered nearly 20 percent of his body on his back and arms.
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