Shocking footage shows a cloud of dust with people running for cover as the building partially collapses.
At least one person has died, three are missing and 19 have been injured.
One witness said: “It was a deep, rumbling sound, like an airplane maybe. It drew my head immediately.
“It looked like the concrete just slid from the top all the way down to the street.
“One guy – I don’t know how he was spared – there was rubble all around him.”
The Hard Rock Hotel was due to be opened next spring.
This is a breaking story. More to follow.