It's just a drill, but it could end up saving lives should the worst ever happen at the Bluegrass Army Depot.
Many people across central Kentucky took part in an emergency responder drill on Wednesday.
They practiced what they'd do if dangerous nerve or mustard gas ever escaped from the depot.
Jacobson Park in Lexington was one of the practice sites.
The drill is designed to test and evaluate the emergency response of several agencies, including schools, hospitals and the Army.