Eyewitness on the bridge saw workers using jackhammers, saw collapse beginning, and “just gunned it” to escape. -—Fox News report of 911 call
Lets get this straight, a jackhammer would not cause a bridge to collapse.
Resonance occurs in things mechanical and can literally tear a structure apart;in the old days Tesla is reported to have stopped some experiments involving low power mechanical devices when the building began to shake. Few things are as repetitive as a jackhammer.I've also been in a position to feel the ground shaking a dozen yards away from an unmuffled large-bore IC gasoline engine (evidently there was a buried shelf of rock).