Fourteen people were injured when winds up to 130km/h collapsed a metal structure at a Backstreet Boys concert in Oklahoma.
The band opted to cancel the show, saying: "We never want to put our fans in harm's way."
Officials were evacuating fans when heavy rain and strong winds knocked over the concert entrance trusses, the WinStar World Casino and Resort in Thackerville said.
The venue said it had asked fans to seek shelter from the storm.
"However, about 150 patrons who were standing in line for the Backstreet Boys concert did not heed staff's warnings," the statement read.
The entrance then collapsed on them when the storm hit.
All of those injured were taken to hospital, with two having been released.
The Backstreet Boys said they will reschedule the concert.