Theres an old urban legend about an airliner dumping its waste (either intentionally or accidently) up at 32,000 feet or so. The waste froze into an icicle in the 20 below tempratures and plumeted to earth striking some poor bastard, impailing and killing him.
I dont believe it myself as I dont think the waste can be dumped without a hose attached. But the legend is out there.
http://www.darwinawards.com/legends/legends1999-02.html