BOSTON (CBS) – If you are out and about Saturday, you may see an unusually large presence of emergency personnel and vehicles.

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WBZ NewRadio 1030’s Kim Tunnicliffe reports

It’s called “Urban Shield,” a 24-hour emergency preparedness drill organized by Homeland Security with police, firefighters and EMT’s from Boston and eight surrounding towns.

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Brookline Police Chief Daniel O’Leary says several simulated crisis events will take place around the region simultaneously, including an emergency drill on the water.

“The federal government has given us a lot of money to protect Boston Harbor, so we’re going to test the assets on different things. There’s three different scenarios that are going to take place, so we’re going to test the response of the fire boats, the police boats and the United States Coast Guard is going to be working with us too,” he told WBZ NewsRadio 1030.

There will also be a mass casualty incident to test eight hospitals and simulated disasters on the subway to test Transit Police.

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The day long event will take place on the USS Salem in Quincy, the former Circle Cinemas in Brookline and the UMass Boston campus.