A few years ago while on vacation with my extended family, all my brothers and I decided it would be fun to drop dime size chunks of dry ice into a water bottle

A few years ago while on vacation with my extended family, all my brothers and I decided it would be fun to drop dime size chunks of dry ice into a water bottle with a few inches of water in them and then throw them into the pool. We did this and given a few minutes they would explode, harmlessly - not much more than a fire cracker. Then we had the bright idea of tying a 5lb weight to the water bottle and let it sink. This was a bad idea on our part. When it exploded, it sent a shock wave through the ground. It was pretty intense make us brothers kinda freak out. People rushed from inside the house and asked what explosion was. We were afraid we had cracked the pool, the concussion wave was so strong. Luckily, we hadn't for my brother's sake. It just makes me think twice before containing dry ice.