I expect it was nitrogen triiodide, made by dissolving iodine in ammonia. It is a contact explosive. I never tried it myself but I heard tell of sprinkling some on a sidewalk and people who walked on it would feel little explosions under their feet. One guy told me he made some then poured it down the toilet. The pipes pinged every time he flushed, for a couple weeks.
When I was in high school, some students put nitrogen trioxide on the hallway floor on the night of the open house - good times.
Yeah, stray wires is all it takes. There was a report of a possible bomb in the street median outside of our building, years ago. It turned out to be a Kleenex box with a bunch of fluorescent light ballasts in it. The bomb robot got to come out for that one.
Yes! I remember that stuff!!! We tried making it after school in the chem lab, but never got it pure enough? I dunno what the deal was. It was (somewhat) under the supervision of our chemistry teacher. By “somewhat” I mean that he was in the room and just trusted us enough not to set the place on fire. But he and another chemistry teacher had a jar of phosphorus in oil (? some sort of liquid medium) and he wanted to show us how it reacted with air. He carefully took it out, and, when not much happened, just left it in the sink or something, and we went about our business trying to create NI[sub]3[/sub]. A few minutes later, apparently enough of the oil or whatever it was (looking online, it looks like it was just simple water) had dripped off the phosphorus that it started reacting with the air, filling that corner of the chemistry lab with smoke and then set itself on fire. Good times.