The center of San Francisco's shopping district turned into an impromptu battlefield Tuesday.
Cable car operators from across the City descended on Union Square for the 48th annual Cable Car Bell Ringing contest.
The annual celebration of everything "ding" pits Muni conductors the chance to show off their bell ringing skills. The one with the "sweetest" ding will win the Grand Prize Ball.
San Francisco's famed cable cars use the bells in daily life to announce a stop or its presence.
Published at 1:32 PM PDT on Sep 28, 2010 | Updated at 1:45 PM PDT on Sep 28, 2010