Place the world below in your saves folder. What is special about it is I set off enough TNT to nearly crash minecraft, and than saved and quit to the title screen (or maybe I force quit minecraft?). Anyway, Attempting to load the world will boot you back to the title screen and the world will not load for about a minute. During that minute you can do whatever you wish in minecraft (that you normally could do) before the world loads. If you open the world, then after the title screen appears, load the world again, and then after the title screen appears the second time, load a normal world, the world will be very laggy. After about thirty seconds, the glitched world will load and the "connection lost" screen will pop up. Do not do anything, and the glitched world will attempt to load again and crash minecraft.