Two people were killed after a television news helicopter crashed near the Space Needle in Seattle on Tuesday morning, authorities said. Investigators have begun searching through wreckage and records to try to determine the cause.

SEATTLE -- Witnesses to the fatal crash of a news helicopter near the base of the Space Needle told officials they heard “unusual” noises that sounded like an engine “whining” as the helicopter took off Tuesday morning after a quick refueling, a National Transportation Safety Board official said. 

Investigators trying to determine what caused the fiery crash will examine the pilot's background and the remains of the aircraft. They will also consider environmental factors such as the weather, said Dennis Hogenson, the NTSB’s acting deputy for the Western Pacific region.

An Emmy-award winning photojournalist, Bill Strothman, and the helicopter pilot, Gary Pfitzner, both died on impact when the copter crashed on the street about 7:50 a.m. 

Richard Newman, 38, escaped from one of three cars damaged by the crash, and was hospitalized in serious condition with burns on up to 20% of his body.

PHOTOS: Helicopter in fiery crash near Space Needle

After a refueling session of less than 30 minutes on a rooftop helipad, the 11-year-old Eurocopter AS350 was taking off en route to Renton, Wash., Hogenson said in a televised news conference. 

The helicopter immediately began to rotate counter-clockwise, then sank toward the ground and burst into flames as horrified workers watched from office windows, witnesses told authorities.

The wreckage was expected to be taken later Tuesday to a hangar at Auburn Municipal Airport about 30 miles away. A preliminary report on the crash should be available within five days, the NTSB said, though investigators may not have determined a cause by then. 

Hogenson said the helicopter was assembled in Grand Prairie, Texas, and is owned by St. Louis-based Helicopters Inc., which operates a nationwide fleet of news helicopters. KOMO-TV and KING-TV jointly leased the downed helicopter.

Daniel Alejandro Gonzalez, 22, a student at Seattle Central Community College, was outside the television station on Broad Street smoking a cigarette went the helicopter went down.

“I heard the engine come on, and about 15 seconds later I heard it sound heavy,” he told the Los Angeles Times. “I hear a ding, ding, ding, and then I heard a crash.”

“We mourn the loss of a couple of our co-workers today,” KOMO anchor Dan Lewis said on the air. “It's so difficult for us to look at this scene, of the wreckage down there.”

Strothman worked for many years at KOMO, earning 13 Emmy awards during his career. After retiring, he worked as a freelancer and also as an employee of the helicopter leasing company. Pfitzner was well known to KOMO employees.

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