New video shows the moment a crane collapsed in South Lake Union Saturday afternoon. Four people were killed when part of a crane from the construction site of a future Google building fell onto traffic below. 

Scott Gaines was on his way to work when the dashcam in his car captured the collapse.

The Seattle Fire Department said one woman and three men were dead before the first firefighters arrived at the scene. Seattle Public University confirmed that freshman student Sarah Wong was one of the victims.

Emergency crews responded to the scene at Mercer Street and Fairview Avenue in the South Lake Union neighborhood around 3:30 p.m. 

“It’s a horrible day in Seattle when something like this happens right in the heart of our city,” Mayor Jenny Durkan said. “Most people have driven down this road at some time in their lives. But it’s a time when we come together because Seattle is a city that rallies around each other.”

Several people told KING 5 that they witnessed crews working to dismantle the crane earlier in the day.

The Washington state Department of Labor and Industries is leading an investigation into the cause of the crane collapse.

Tim Church, a spokesperson for Labor and Industries, confirmed investigations into four companies: GLY Construction, subcontractors Northwest Tower Crane and Omega Morgan, and Morrow Equipment Company.

Half of the cranes in the state of Washington are in Seattle.