I took a physics class my senior year of high school. One day, we were assigned an in-class project to make radios by wrapping copper wire around cardboard paper towel tubes. (And I think there was a magnet in there somewhere. All science things have magnets, right?) After class, we lined all of our radios up along the counter so we could come back the next day and finish them.
Coincidentally, a disgruntled student (not from my class) called in a bomb threat that next morning. We students got to stay home while the police searched every classroom high and low. As my Physics teacher later recalled, when he unlocked his classroom door for the police, they saw the 40 copper wire enshrouded cylinders stacked on the counter and yelled, “Holy shit!” They thought they had just uncovered the largest bomb ever seen in Nevada County.
And as I recall, no students were suspended.