My boss had to tow in a crashed bike today. Luckily no one was injured, but it was the result of an improperly tied down backpack.
The backpack was tied down to a rear carrier in between 2 hard bags. It apparently came loose and ended up getting snagged by the back tire. The contents of the backpack were enough to wedge in between the tire and swingarm and cause the rear tire to lock up. Needless to say the rider went down at highway speed and damaged the bike pretty good.
There was also another rider behind him that couldn't manage to stop in time and also laid his bike down.
Just a word of warning, if you have to carry items with you make sure they are properly attached.
Ride safe ev1