I went down a sinkhole once when I was young. In fact, I was just a baby and my mother was bathing me in the kitchen sink when I accidentally kicked the stopper loose.

In a flash I was gone with the bathwater! A huge sucking sound, a roller-coaster ride through the P-trap, and there I was, a naked little child, surfing (so to speak) through the city's sewer system.

Fortunately, everything came right in the end.