It happened at the "Mumford and Sons" show Wednesday night at Forest Hills Tennis Stadium.
This was the venue's first show in 16 years.
Many disappointed fans were turned away.
Some say it was so crowded inside that they didn't feel safe.
A spokesman for the stadium told Eyewitness News the concert was not oversold.
He says there was a problem with getting fans onto the upper deck.
He claims fans that couldn't get in will be offered refunds.