DENVER (CBS4)- First responders completed an unusual exercise near the 16th Street Mall on Thursday afternoon.

They were practicing the best way to decontaminate a vehicle.

As part of the exercise, a car was placed in a large clay berm while a firetruck pumped a saline solution over the car to cleanse it.

The exercise was planned to begin at 2:30 p.m. and end at 4 p.m. in the parking lot along California Street between 15th and 16th.