In our current campaign (all who are first time players bar myself and our dm) my party found a bag of holding and proceeded to destroy it within 2 minutes.

We were travelling through a cave and came upon an underground river with a strong current. It was too wide to jump so I took our dwarf monk on my shoulders and preceded to walk through it with my goliath barbarian rolling a strength check against the current. Cue a nat 1. I slipped and we got swept away and ended up in a little cave underwater with a small pocket of air. Seconds later we were met by our rogue changeling who decided to just dive in and follow.

I couldn't see in this cave as I don't have darkvision, however my 2 party members could and spotted a bag in the hands of a skeleton. After putting something in the bag our rouge quickly realised what it was. As we were trying to figure out ways of getting out of this small cave our rogue placed it in the water and opened it, causing the river to flow into the bag.

Our DM was absolutely stunned and had to take a second to look up the bag's properties.

Long story short, a bag of holding cannot hold that much water, exploded and we almost drowned. I still think it was borderline genius and idiotic.