Just so you all know, the poo is contained in tanks, then emptied when the plane arrives at its destination. On rare occasions a tank leaks its contents, including a blue disinfectant, fall to earth. Because it's so cold so high up, the chunks are frozen when they land and are referred to as "blue ice." Toilet waste has been known to hit people down below. One of the first reported cases occurred on Oct. 10, 1974, when a block of blue ice pierced the roof of Erma Schuon's apartment in USA, missing her by about 6 feet. The latest incident occurred in September 2002, when blue ice crashed through the roof of Susan and Kenneth Selzer's ranch-style house in North Massapequa, N.Y.