STILLWATER, Oklahoma - Stillwater residents may hear gunfire coming from Boone Pickens Stadium Wednesday, but police say it's just part of an elaborate training exercise.

A large-venue police response training course is very rare at American universities and Stillwater Police say Oklahoma State University is one of only three in the U.S. to host this exercise. 

The exercise last from Wednesday through Friday.

Police say it's part of a course designed to prepare officers for worst case scenarios.

They say law enforcement personnel from around the country will be there. They say the company that conducts the drill uses full-time SWAT members and has done them at pro baseball, basketball, football and hockey venues across the U.S.

Police add they take extreme precautions to make sure the public is safe during training, so they can learn to keep people safe in case the worst happens.