TOWSON, Md. — Local emergency responders will test their ability to handle a large-scale, mass-casualty accident in an exercise scheduled the morning of Sunday, June 4 in the Security Square area.

The Baltimore County Fire Department and Office of Homeland Security and Emergency Management will organize and oversee the drill. Participating agencies include the State Highway Administration; the Maryland State Police; the Mass Transit Administration; and area hospitals.

The mock incident will occur on eastbound I-70 near the park-and-ride at Security Boulevard and will involve many pieces of emergency apparatus. Residents can expect to see and hear unusual activity beginning about 8 a.m.

All of I-70 inside the Baltimore Beltway will be closed in both directions, from the park-and-ride to I-695, from 6 a.m. to 2 p.m. Message boards will be in place to direct traffic, and travelers may use Security Boulevard as an alternate route.

The scenario involves a bus accident between two Mass Transit Administration buses and a box truck. About 100 "patients" will be triaged, treated and transported to Northwest and Sinai hospitals. Simultaneously, another 160 patients will be sent directly to Franklin Square Hospital Center, St. Joseph Medical Center and Greater Baltimore Medical Center. Five patients from GBMC will be evaluated at the Sheppard Pratt Health System.

"We test periodically to make sure that public safety agencies from across the area are ready to work as a team in the event of a disaster," said Richard Muth, director of the Office of Homeland Security and Emergency Management.