LEWISTON – About a dozen fire, police and rescue agencies participated in a mass-casualty disaster drill at Bates College in Lewiston on Saturday.

The mock accident – a bleacher collapse that hurt more than 20 people – allowed the groups to test themselves under a simulated, but realistic, situation, according to Brad Gilbert, a project coordinator for United Ambulance whichhelped organize the drill.

The drill involved a Life Flight helicopter and both St. Mary’s Regional Medical Center and Central Maine Medical Center. It also included the Central Maine Regional Resource Center, United Ambulance, Auburn and Lewiston police and fire departments, Lisbon and Mechanic Falls emergency personnel and Bates College emergency and security workers.

Gilbert said it was too early to say what the groups learned from the drill, but “It was a really good drill.”

Forty to 50 people participated as victims, including a local Boy Scout troop.