A toy gun shut down an entire university Wednesday, the St. Louis Post-Dispatch reports.

It all started when an engineering class at Saint Louis University (SLU) asked its students to create a rubber band gun as an assignment. One of the toys apparently fooled one student who thought there was a gunman loose on campus. After a brief moment of panic, authorities issued a lockdown order that affected the entire campus.

The university issued the “shelter in place” order at about 5 p.m. after the report of a potential shooter and a second — again mistaken — report of gunfire.

By 7:15 p.m., it was all over and the university indicated, “All clear. Campus is safe. Resume all normal activities.”

A witness has first reported seeing an individual dressed in a black hoodie heading for a college dorm with what looked like a gun.

After questioning two students, police and university authorities determined that the gun wasn’t real.

Jeff Fowler, the SLU spokesman charged with explaining the mix-up, said the first student that police interviewed was the one who sighted the “gun” while the second was the student who was carrying the toy around with him.

Fowler told the Post-Dispatch that the second student led police into his dorm room where he showed them a toy rubber band gun. Fowler did not say how the police reacted to that revelation.

There was no evidence found of any student carrying a real gun or of gunfire at the university.

The toy gun assignment was included in the SLU’s Aerospace and Mechanical Engineering Manufacturing Procedures class. Students were asked to build a device with interchangeable parts. One option was a rubber band gun; that’s what the class selected to do.

Following the lockdown, the university asked all students in possession of the rubber band guns to conceal them in closed container and bring them to an SLU office for destruction.

“This is the first time toy guns have been made in this class, and it will be the last,” the university said.

Fowler cheered the efforts of police and campus security. “You can never take incident like this lightly,” he said. “It is much, much better to be safe than to be sorry.”

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