I was climbing down a ladder at a tower in grishino (the one next to the barn and well on south end). I had my gun in my hands and went from a prone position to crouched position before entering the ladder to climb down. I used shift to fast slide down and went I reached the bottom I fell through the earth and kept falling until eventually landing in some type of water and I was just swimming in darkness. Luckily I logged out and back in on another server and I was above ground standing in the grass.