SEATTLE -- Seattle has more tower cranes than any other city in the country.
That fact alone has many in the city asking: What went wrong on Saturday?
State Labor and Industries investigators will look closely at the video that captured a crane Saturday crashing into Google's new campus. The crash killed four people, including two who were working to dismantle the crane.
Experts say hearing from those directly involved when the crane fell will be vital.
James Pritchett of Crane Experts International said the manufacturer of the crane is incredibly specific on how to take it apart. Whether or not it was being correctly dismantled will be up to investigators.
"Those statements are just so vital because you're going to have to reconstruct the accident," Pritchett said.
The state is investigating the five companies involved. The companies include:
Seattle-based expert Terry McGettigan has compiled the numbers on crane accidents. He says the highest percentage of catastrophic accidents happen when the crane is coming up, or being taken down.
In a 2012 collapse near Dallas, investigators found crews cut corners and removed bolts from the vertical tower to save time during dismantling. That's one thing investigators will be considering, Pritchett said.
There are also questions as to why Mercer Street wasn't closed during the dismantling process. The Seattle Department of Transportation says it had a permit to close a section of Valley Street, but not Mercer.