Workers at the rodeo were able to stop the bull, named Rewind, by pinning it up against the fence.
Four people were hurt, but only one needed to be hospitalized.
Rodeo officials are reviewing what took place and rodeo commissioner John Windwick said it was the first such incident in the event's 37-year history.
The bull riding events continued Friday following the incident, and the rodeo resumed as scheduled Saturday afternoon.
The Associated Press contributed to this story.