The drill was a surprise to students. However, a bullet found in the school late yesterday was a surprise to the administration. So, police took today's drill a step further by sweeping the entire building.
Because K-9 units were brought in it was necessary to evacuate the building. Students and faculty stood outside for over an hour while the search was underway.
In the end, it does not appear that anything significant was found. That does not mean that the police will not be conducting a thorough investigation as to the origins of yesterday's bullet.