NEW YORK (CBSNewYork/AP) — The New York City region’s emergency agencies are practicing for a disaster.

The city’s Office of Emergency Management ran a training exercise Wednesday that simulated a response to a 10-kiloton nuclear device exploding at 42nd Street and Seventh Avenue in Times Square, WCBS 880’s Rich Lamb reported.

According to the exercise, 100,000 people were instantly killed; a wave of overpressure took down buildings for a half-mile radius and did damage for up to two miles; and a radiation cloud swept over the region.