Dry Ice in the Toilet.
What happens when you put dry ice into an airplane toilet at 33,000 feet? One unfortunate pilot found out, and the story is priceless.
He turns and looks at the toilet. But it has, for all practical purposes, disappeared, and where it once rested he now finds what he will later describe only as a vision. In place of the commode roars a fluorescent blue waterfall, a huge, heaving cascade of toilet fluid thrust waist-high into the air and splashing into all four corners of the lavatory. Pouring from the top of this volcano, like smoke out of a factory chimney, is a rapidly spreading pall of what looks like steam. He closes his eyes tight for a second, then reopens them. He does this not for the benefit of unwitnessed theatrics, or even to create an embellishing detail for eventual use in a story. He does so because, for the first time in his life, he truly does not believe what has cast itself before him.