Federal investigators are reviewing a number of scenarios to determine what caused a news helicopter to crash into the pavement near Seattle's Space Needle, killing two men on board and seriously burning a third on the ground."I'm confident that we're going to figure this out," said Dennis Hogenson, with the National Safety Transportation Board, said at a news conference Wednesday afternoon.

KOMO News reports that Hogenson says they're looking at all possibilities, including what role, if any, construction cranes in the area played.

A crane operator was in radio contact with the pilot on a prior landing on the rooftop helipad, though there's no substantial evidence to link the cranes with the crash, Hogenson said.

Investigators also are poring over pilot, maintenance and company records, and they will recreate the crash scene to look for anomalies, he said. Wreckage from the helicopter has been moved to a secured hangar in Auburn, about 30 miles south of Seattle, where the team will lay out the pieces to determine what parts potentially are missing.

A large portion of the helicopter, which was built in 2003, was made of composite material that burned, so "a lot of those parts and pieces are simply gone," Hogenson said.

It may be months before federal investigators know what caused the KOMO-TV news chopper to hit the pavement and burst into flames Tuesday, setting three vehicles ablaze and spewing burning fuel down the street.

While a preliminary report could be released as early as this week, Hogenson said a final report could take up to a year.