Ok, I'll share a story that happened to me, but first let me tell you about what I had wanted to build when this happened. Ok, I had this idea for a massive sandstone temple underground, specifically in this one perfectly round lake in my minecraft world. I had it all sketched out and even figured out how to do a super cool courtyard. Now the lake was fairly shallow so you could see the bottom pretty well (this was ideal since I wanted sunlight to shine into the courtyard through glass, which would keep the courtyard from getting messed up by the water). I started to build my creation, but I like to build in survival mode (which led to a lot of invediting), so I had to figure out a way to not get lost in the temple, specifically when I was doing the maze part. I lit up my path with torches and placed a redstone torch every now and then on the tunnel walls to let me know which way I had gone.
Anyway, my temple was nearing completion and I had been underground for what seemed like ages, so I decided to head to the surface for a break. I wasn't worried about monsters because my game difficulty had been set to peaceful. Down the long halls I went, admiring my progress when I saw that one of the halls had flooded and that water was pouring in from holes in the tunnel that I didn't remember making. I did remember that I had made some water features in the temple and thought I had knocked out a block accidentally. I plugged it up and fixed everything before continuing on my way. More and more leaks had appeared and I had no idea why. I didn't have creepers, I had never spawned in tnt, so I figured that my brother had messed with my game. It wasn't until I was nearing the entrance of the maze that I ran into some serious trouble. I had tried to swim through another flood to get rid of the water when I became trapped in the current. I cursed a bit and tried to get out, when I heard an explosion above me. The whole roof was gone and my character was starting to drown, so I began swimming up. The surface couldn't have been far but the lake had for some reason become so much deeper, I urged my character to swim faster. I could see the light above me, so I looked back to see my ruined temple. All I saw was a massive shadow coming towards me. I reached the surface and swiftly dropped down once more to see what it was. It was gone in the new depths of the lake. Later when I tried to find my temple, all that remained was the flooded courtyard. Everything else had been destroyed.
