The KOMO TV helicopter crashed Tuesday morning while taking off from the station near the Space Needle.
Witnesses say the nose of the helicopter tilted down and the helicopter fell onto three vehicles.
Employees in the building says the helicopter exploded almost instantly. Two people in the helicopter were killed. A person was trapped in one of the cars, but was able to pull himself free. He suffered severe burns and is hospitalized in critical condition.
When fire crews arrived, the helicopter's fuel was on fire running down the street. They were able to stop it before it went into a storm drain.
The cause of the crash is not known. The NTSB has started an investigation.