What is the absolute worst thing you ever smelled?

At one of my brother's baseball games they emptied out the porta potties. The smell was so bad I almost threw up. I had no idea why they would decide to do it in the middle of a baseball game. Why not wait until there are no games? The umpire stopped the game because all the players were coughing. Worst part was the temperature that day was sweltering. It was so humid it felt like the heat was wrapped around you, so the smell lingered. It was nasty. My sister had used it before they emptied it and said it looked like someone squirted mustard in there but the smell told another story.

Alright, now I want to hear your gag-worthy stories!