BOSTON (CBS/AP) — Emergency responders were staging a daylong training exercise involving a series of staged crises, from an “active shooting” event in Brookline to the rescue of elected officials held hostage at Boston City Hall.

The 24-hour training exercise on Saturday, dubbed “Urban Shield,” is meant to simulate large-scale public safety incidents.

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“It gives them the opportunity to think the unthinkable,” said WBZ-TV Security Analyst Ed Davis. “This realistic on the street type of incident driven training makes all of the difference in the world.”

The exercise included about 2,000 personnel from the region including police, firefighters, EMTs and hospital staff.

WBZ NewsRadio 1030’s Kim Tunnicliffe reports

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The goal of the exercise is assess the ability of public safety personnel to successfully respond to, and manage, multiple public safety threats and emergencies occurring simultaneously throughout the metropolitan Boston area.

“What you saw in the Boston Marathon, there was multiple victims, and a lot of need for medical aid quickly, and that’s what we are trying to test,” said Cambridge Police Lt. George Sabbey.

The 11 staged public safety scenarios are based on past real-life events and include an “explosive device” found in the transit system, an “injured officer” situation in Cambridge and a “parking lot collapse” in Boston.

(TM and © Copyright 2014 CBS Radio Inc. and its relevant subsidiaries. CBS RADIO and EYE Logo TM and Copyright 2014 CBS Broadcasting Inc. Used under license. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.)

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