HAMILTON, OHIO: Authorities plan a large-scale school safety exercise involving 11 districts in Ohio.

The Butler County Educational Service Center in southwestern Ohio says nearly 200 students and adults will take part June 18 in the simulation of an active shooter at a board meeting on the Ross Local School District’s high school and middle school campus.

Katharine Clayton, the center’s director of public school safety, says it will be “a complex, coordinated event.” About a dozen county, state and local agencies and community partners will participate in what’s expected to be the biggest such safety exercise ever in Butler County.

The full-scale exercise will meet Ohio requirements with mobilization of personnel and equipment and a command post.

School resource officers from the districts are invited to observe the planned four-hour exercise.