A school in Austria was evacuated after it was discovered what has been displayed there for a very long time without anyone realizing it. It happened during science class as the teacher was giving a scientific demonstration with a Geiger counter. He laid his watch on a shelf in the classroom which is 20 times greater than normal. But when he switched on the Geiger counter, he began getting unusually high readings, much greater than could have emanated from the watch. So, he began walking around the room, tracking down the source of the readings.
As he moved about, he honed in on the source that was coming from a group of rocks in a display and the Geiger counter went off the charts with a reading 2,000 times greater than normal. He then realized the rock was actually uranium that was unshielded. He cleared the classroom and notified school authorities who evacuated the entire school as experts were brought in to deal with the situation.
An alert was sent out to other schools in the region, where another 38 rocks containing uranium were found in 11 other schools. There has been no indication that any student or teacher who were sickened by the material, although there was that threat. The rocks have been moved where it can be safely stored until a decision is made what to do with it. Uranium can be used to fuel nuclear plants generating electricity or in building a nuclear bomb.