Some music legends are remembered for their songs. Others, for their unforgettable live performances. And then there’s that one time in Chicago when the Dave Matthews Band went down in history… for all the wrong reasons.

It was a sunny August day in 2004 when the band’s tour bus crossed the Kinzie Street Bridge. What happened next can only be described as a rock-and-roll horror story with a very unpleasant twist. The bus’s driver decided it was the perfect moment to empty the septic tank. Unfortunately, directly below, a boat full of wide-eyed tourists was enjoying one of Chicago’s famous architecture cruises.

Instead of gazing up at the skyline, more than 100 passengers suddenly found themselves part of an unwanted shower — 800 pounds of human waste cascading through the bridge grates. It was less “Crash Into Me” and more “Splash Onto Me.”

Read More: When Spielberg made us weep and Robin S made us dance

Dave Matthews Band’s Bizarre Chicago Folklore

Needless to say, the boat rushed back to shore, passengers rushed for a change of clothes, and the incident rushed straight into the hall of fame of bizarre music-related moments. The driver eventually faced the music in court, while the band, mortified, issued apologies and settled up with some hefty fines and donations.

Today, the story is a piece of Chicago folklore — equal parts gross and giggle-worthy — and proof that sometimes rock history isn’t written on stage, but on a bridge. And if nothing else, it’s a reminder that when you’re cruising down the river, it’s not just the weather you need to watch out for.