You obviously don't have teachers like my old highschool chemistry teachers Mer. Roell and Mr. Drews. They LOVED explosions (also because afterwards they had the full attention of the now widely awake students!).
Mr. Roell once blew up a large balloon filled with a hydrogen / oxygen mix in the school corridor outside the chemestry lab, by using a candle attached to a broomstick. All doors and windows flew open and he was lucky no glass got broken.
Mr. Drews demonstrated the explosive properties of a mix of red phosphorus and potassium chlorate to us (don't try this at home unless you REALLY know what you are doing, the mix is just as powerfull and sensitive as nitroglycerine and will explode violently if you just give it a bad look). He also liked to build small cannons out of cardboard tube and fill them with some carbide and water. Then he would use them to shoot rubber stoppers around the lab.
At another time, a student brought a drill hand grenade with him, which he had found on a nearby US Army training site. Obviously it got confiscated by his teacher and left in the techer's breakroom/office. At the end of the day, Mr. Roell found it still on the table and decided to get rid of it (qute:" After all I used to be in the Bundeswehr!" (German Army)).
He decided to pull the ring and to throw it out of the window into the empty school yard.
At this time only one other teacher was still around, a very quiet lady English language teacher.
He must have forgotten something about handling grenades (I assume that he didn't hold down the handle), in any case the thing exploded just after leaving his hand, still in the office. He told us that he was standing there, with a ringing in his ears and full of chalk powder (from the grenade), counting his fingers, while the Englisg teacher was having a hysterical fit....
Je Suis Charlie et je suis Ahmet aussi