I found this video to be genuinely scary.
Watch a couple of trees disappear straight down into a sink hole in Bayou Corne, Louisiana.
Every time I watch this I keep expecting to see Cthulhu emerge from the water.
The sinkhole was spawned by a mining procedure known as “injection-mining” which, from the description, seems just as horrible as the name implies. The state of Louisiana has filed a lawsuit against Texas Brine Co. over the town’s demise.