Well...there went the Gullywhumper. On May 17, 1997, this overloaded Keel Boat was rocked side to side and then rolled over, with 49 guests aboard. The vessel was not designed to hold this capacity, especially with guests seated on the highest deck.
The photograph above shows the Disney team taking a look at the wreckage. This dumb accident led to the complete closure of the attraction. Now the Gullywhumper rots along the Rivers of America as a "prop." Doh!