KOMO News confirmed the helicopter was theirs, and was used in a joint partnership between KOMO and KING 5.
Emergency crews rushed to the crash scene to extinguish the flames, just feet from the Space Needle, on Broad Street next to Fischer Plaza, home to KOMO TV.
Two people in the helicopter were killed instantly, and a third person, a 37-year-old man was extracted and transported to the Harborview Medical Center in critical condition, the Seattle Fire Department said in tweets.
KOMO News tweeted that the helicopter was lifting off from a rooftop at Fisher Plaza when it crashed. Anchor Kelly Koopmans, who was inside the newsroom at the time of the crash, said they could hear "the chopper swirling down to the ground" as it happened.
Investigators from the National Transportation Safety Board and the Federal Aviation Administration are en route to the crash site, the fire department said, adding there was no indication of terrorism.
2 DOAs at helicopter crash scene near space needle. pic.twitter.com/JwhBs2nYUF— Seattle Fire Dept (@SeattleFire) March 18, 2014
We heard the chopper swirling down to the ground. Rushed out to see the unbelievable, our @komonews chopper crashing into at least 2 cars— Kelly Koopmans (@KellyKOMO4) March 18, 2014
Flames now out, told by a witness one person on fire when crawled out of a cars. 1 responders working on that person pic.twitter.com/zHeFzV0qzJ— Kelly Koopmans (@KellyKOMO4) March 18, 2014
Chopper tail visible amid the smoke & car wreckage pic.twitter.com/uZ57DibreU— Kelly Koopmans (@KellyKOMO4) March 18, 2014
Medics transporting an approx 37 yo male to HMC in critical condition self extricated from car pic.twitter.com/hhVAX0qmbs— Seattle Fire Dept (@SeattleFire) March 18, 2014
This investigation will continue for many hours. Please stay away from area. We will update with information as we learn more.— Seattle Police Dept. (@SeattlePD) March 18, 2014