HIALEAH, Fla. – Hialeah Elementary School students got a nifty science lesson this morning when the police came to their school and exploded a pressure cooker.

Someone apparently reported the contraption sitting under a tree about five feet from a kindergarten classroom shortly after school started and officials evacuated the building’s 600 students, NBC Miami reports.

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Police blockaded roads and huddled students away from the building on campus, as the bomb squad analyzed the cooker, eventually blowing the lid off. Nothing happened. It was just a pressure cooker somebody threw under the tree, according to WSVN.

Hundreds of parents gathered outside of the school’s perimeter, worrying about the commotion, as police made multiple sweeps of the building and surrounding area before giving students permission to re-enter.

NBC Miami reporter Sharon Lawson described the incident as a “very strenuous for students and staff.”

“It appears someone just discarded the pressure cooker under a tree, not intending to cause a disturbance to class,” she said. “This was just a false alarm, probably somebody really didn’t know that they really need to put the pressure cooker in the garbage area, and not just leave it under a tree because a situation like this could unfold.”

Some folks who commented online aren’t convinced the cooker isn’t part of a terrorist plot.

“A possible test run? Or seeing how and where people evacuate?” reader Cthulhu66 questioned on the ABC News site. “I wouldn’t write this off as a simple prank so quickly.”

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“Poor kids. This is what we have now,” Scott added. “This is where we are going.”

“The terrorists win again. They don’t even have to try: any randomly placed inanimate object does their job for them,” WerewolfWounds posted to WSVN. “’An abundance of caution’ is destroying our way of life. So is being PC on every issue.”

Others cracked jokes about the situation.

“Wondering what kind of person thinks this is funny,” Brian Levine posted on the ABC News site.

“Probably a crackpot,” Not Amused countered.

Other cracked jokes.

“As a result, Mrs. Lipton’s class never got the chili dip for their class potluck,” paddyk posted.

“They discovered short ribs and had lunch,” INUnivHoosier commented.

“Must be some overt act of micro aggression. The principal needs to resign over this,” DJ wrote. “The kids need a ‘pressure cooker free zone’ on the playground.”