I was trying to reproduce the bug where TNT minecarts on a circle track explode violently, but I couldn't. After only getting 3 minecarts with TNT on the track, the game started to lag severely, crashed, and then the attached crash report came up.

I expected a large hole in the ground.

Instead, the game crashed, and left a puzzling explosion pattern. Upon reentering the game, I took a screenshot of the resulting explosion.

Steps to Reproduce:
1. Arrange 4 normal tracks in circle
2. Place multiple Minecarts with TNT on the track (you may have to move around to get them all on).
3. After getting 3 on the track try to place a fourth one. I couldn't, and after multiple tries the game lagged and crashed.

I run quite a lot of heavy stuff on my machine; this crashed it though, and it wasn't even a large explosion.