HOLLIDAYSBURG, BLAIR COUNTY, Pa. (WTAJ) — When you hear it, you think of every possibility, other than the reality.

“A nail gun. Also, I thought, when they were outside of the high school, right outside of my office, it sounded like a bird hitting my window or a board dropping. It sounded like a construction site,” Dr. Maureen Letcher, Principal of Hollidaysburg High School said.

Teachers and staff at Hollidaysburg Area High School took part in an active shooting training on Friday afternoon. School Resource Officer Wayne Bush has 30 years of law enforcement experience. During the drill, he shot blank ammunition from three different types of guns inside and outside of the school, while notifying teachers where he was located.

“Most of these teachers will finish out their careers in teaching having never had to deal with a violent event. Most students are gonna finish out their school experience having never had to deal with a violent event, but that doesn’t mean we don’t have to prepare them for it,” he said

Bush said giving teachers an idea of what gunfire sounds like from a shotgun, AR-15 and revolver can save precious time and lives.

“Those seconds that people are in denial, or don’t realize what it is, those are critical seconds that they can be using to save lives, rather than wonder what it is,” he said.

Although the rounds were blank, the sounds and the emotions were all too real.

“The first shots that were fired were very ere. You just got goosebumps all over, in a bad way, and all we kept saying was, ‘Please don’t ever let us every hear this for real’,” Letcher said.

And while the possibility will always exist, exercises like these bring a sense of preparedness for what they pray never happens.