I just got back from Chicago where I learned the sweeper I posted above was nearly destroyed in the Blackhawks parade. After the buses carrying the team made their way down the parade route the crowd pushed through the barriers and flooded the street. The sweeper got caught in the crowd and people began climbing on it and shaking it. After calling 911 the operator was pulled from the machine.
If you're interested here's a time lapse video of the parade. About the 2:30 mark you see the sweeper in the crowd.
http://www.youtube.com/watch?v=wWRvvzTjLUY
Here's a short clip of people crawling on the sweeper. (There is profanity.)
http://www.youtube.com/watch?v=sbJanTlFuPM