Second attempt at commuting back in 2008, too scared to ride on the road so I was on the sidewalk, one pad of sidewalk missing which was never a problem in the afternoon, but after the sprinklers had just shut off in the morning the ground was very spongy. My front wheel sunk in and then hit where the sidewalk started again and I was catapulted over the handlebars in a classic face plant. Landed on my chin and helmet. Minor scratches, cracked the helmet. Ruined the bike.