Silence as it fell from platform?
Seattle PI (newspaper web site) is reporting:
"Gary Knapinski, a construction worker from Snohomish, said he was walking to his car when the helicopter dove to the ground.
A panhandler was shouting to him over the roar of the chopper taking off, Knapinski recalled. The next moment, silence descended as the helicopter's engine quit.
As he looked on, he watched the helicopter's nose drop as it fell."
Helicopter crash kills 2 near Space Needle in Seattle - seattlepi.com