The fences at the Canal Days concert were toppled by people wanting to enter.
It happened Saturday night around 10 o’clock at H.H Knoll Park.
Niagara Regional Police were already on scene, and quickly helped event officials get the fencing back in place.
15 minor injuries were reported.
Canal Days organizers say they expected a crowd of a little over 10,000 concert-goers.
However, over 25,000 attempted to attend - which is far more than the space that was available.
The event resumed as scheduled, however alcohol services were shut down for the night.