A woman has died and two more critically injured after a false alarm over a shooting sent the crowd stampeding for the exits.
The fatal crush happened in Rochester, New York state, US, during a concert featuring GloRilla and Finesse2tymes on Sunday night.
The injuries were caused by the stampede, Police Chief David Smith said at a news briefing Monday.
"We do not have any evidence of gunshots being fired or of anyone being shot or stabbed at the scene," Smith said.
As the concert ended just after 11pm, people exiting the venue began to surge dangerously, he added.
Police made their way inside and found three women with critical injuries.
A 33-year-old woman died at a hospital, and the other women two were in critical condition Monday.
Seven additional people were taken to hospitals and treated for injuries that were not life-threatening, Smith added.
"What began last night as a night of live music and fun for the performer GloRilla ended in tragedy with one person dead and two more fighting for their lives," the chief said.
While there is no evidence of shots being fired, Smith said, police are investigating several possible causes of the fatal surge, including "possibly crowd size, shots fired, pepper spray and other contributing factors".
"All I know, it was a lot of running. A lot of people got hurt. I see people on the ground, like hurt badly," one witness told News10NBC.
He added: "It was deathly packed. So I knew I had to get up out of there."
Mayor Malik Evans called the fatal stampede "a tragedy of epic proportions" and promised a through investigation.
"We are going to hold people accountable for what happened last night, period," Evans said.
GloRilla, a Memphis native whose 2022 song "F.N.F. (Let's Go)" with Hitkidd was nominated for a Grammy for best rap performance, tweeted that she was "praying everybody is ok".
Fatal crowd surges have been a recurring disaster at concerts and other large events in the U.S. and around the world, including a 2021 concert by rapper Travis Scott in which 10 people died.
Evans called Sunday's stampede an example of "something that all of us who love concerts worry about."
The mayor, who said he frequently attends performances by his favourite artists, added: "If you go to a concert you do not expect to be trampled.
"Your loved ones expect you to be able to come home and talk about the experience that you had at that great concert."