Myself and a few friends, back when we were around 12-13 years old, had built a modest fire. Longish story shortish... a diet coke can was the only thing to explode (we weren't dumb enough to try things that were clearly explosive). However the can exploded about thirty minutes after we placed it in the center of the fire on top of the small patch of white hot coals. Before that, after about five minutes of cooking, we heard it let out the pressure in a tea-pot sort of way. After about eight minutes it had been poked and smacked a few times to where 12-13 year old children had deemed it inert and no fun. Then, roughly 23 minutes later out of absolutely nowhere the can went off like it was packed with cherry bombs. A serious explosion which sent 1-2kg logs passed our heads, and large chunks of red hot coals as well as flaming chunks of wood at least 5 meters outward. Putting out the fire, and really leaving nothing left in the pit. What could cause that? This was a tiny bit less explosive than blowing up something like a flammable spray paint can... except there was no fire ball or anything. Just a very loud boom. From a little soda can that fits in your hand. And in every other situation, in my experience at least, soda cans + a fire of any sort makes a somewhat loud and harmless popping sound as the container ruptures. Harmless. However this released pressure audibly, then didn't react to being poked or smacked a bit, and after at least 20 minutes exploded with enough force to have blown your hand clean off (at least) had you been holding it. Anyway. Input? Ideas? Is diet coke special chemically? I've never really looked into it, but it came to mind just now and after learning a decent amount of college chemistry and physics... all I can think of is, "Weird".