WORLAND, Wyo. – Police and school officials in Worland, Wyoming are taking heat from parents after a spontaneous “training exercise” left their elementary aged children traumatized.

The idea was to have a school intruder show up on the playground to see if teachers would respond appropriately to usher students away from danger, but that wasn’t exactly how it played out, the Casper Star-Tribune reports.

A creepy looking man with a backpack and hooded sweatshirt pulled over head leered at children on the playground at East Side Elementary around 10 a.m. Thursday, and teacher Kevin Heyer approached the man, who then allegedly ran off, according to the news site.

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Heyer was apparently aware that a random training drill was expected last week and told students “Run! Run!” to the opposite end of an open field from which the “intruder” appeared. But students like Aubrey Truman thought Heyer said “He’s got a gun! He’s got a gun!” and frantically scrambled to the end of the field, where another teacher gathered students by grade, the Star-Tribune reports.

Truman told the news site she thought she was going to die, and couldn’t stop shaking, despite local law enforcement who arrived on scene to tell students the scary ordeal was a training exercise. Regardless, Truman and other students complained about the harrowing experience to their parents, who relayed their frustrations to school officials. Roughly 200 students were involved in the surprise drill.

Truman was so shaken that her mother, Amy Truman, decided to keep the 9-year-old and her brother home from school the next day, according to the news site.

“They took it to an extreme not to discuss this with parents and the community beforehand,” parent Amy Munoz told the Star-Tribune. “It’s a slap in the face.”

“They just think they can do whatever they want with our kids,” she said.

Washakie County Sheriff Steve Rakness led the training, which he deemed a success in an interview with the Northern Wyoming Daily News.

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“We identified some things we need to work on, but otherwise no problems whatsoever,” he said.

East Side principal confirmed that students were not informed beforehand that the unarmed man was part of a drill, but did not return messages for comment. The county’s emergency management director declined to comment on the drill.

“The (district) superintendent denied that the word ‘gun’ was used or that students were directly affected. The exercise, as far as he was aware, typified the district’s lockdown procedure, he said,” according to the Star-Tribune.

The news site reports parents were informed by email May 12 that they planned to conduct a “low-level training exercise” at East Side Elementary “sometime this week.”

“This training exercise will test the response and lock-down procedures of the school and response procedures for local 1st responders,” the email read.

Beyond the disturbing nature of the surprise drill, Munoz and other parents were also concerned that grouping students in an open field might not be the best way to avoid a dangerous person in a real school intruder scenario.

Alda Pedraza, parent of an East Side fifth grader, also questioned why students weren’t informed of the training, as is the case with most fire drills.

“I don’t think we need to scare the kids,” she told the Star-Tribune.