At approximately 5 PM on Wednesday, students and faculty at St. Louis University were ordered to shelter in place amid claims of an armed man on campus and reports of gunfire outside Marchetti Tower East, a dorm a few blocks away.

A man wearing a black hoodie and who may have a hand gun is in Spring Hall. All are advised to stay clear of Spring Hall.

— Saint Louis University (@SLU_Official) May 3, 2017

Shots fired out side Marchetti East shelter in place

— Saint Louis University (@SLU_Official) May 3, 2017

But after officials investigated the claims and cleared the campus, the order was lifted shortly after 7:15PM with an update announcing, “All clear. Campus is safe. Resume all normal activities.”

What had triggered such hysteria and pumped fear into the hearts and minds of thousands of people?

A student walking to class with his assignment: a rubber band gun.

The toy gun was one built by a student in the aerospace and mechanical “engineering manufacturing procedures” class, a news release said. Students were asked to build a working device with interchangeable parts and chose toy rubber band guns out of several options.

The students were warned not to display the guns outside of class but the student police questioned had built a “very realistic” toy gun and openly carried it into Spring Hall, a campus dorm.

The university announced all students’ rubber band guns were collected and destroyed Thursday morning, you know, for good measure.

SLU spokesman Jeff Fowler defended the university’s reaction to the “gunman” on campus.

“You can never take (an) incident like this lightly,” Fowler concluded. “It is much, much better to be safe than to be sorry.”

Perhaps if kids were taught firearm safety and to respect guns at an early age, these types of incidents (and several more) could be avoided. In the meantime, please be on the lookout for these dangerous rubber band guns… if you’ve ever been hit with one, you know – they sting like the dickens.