I tripped on the pavement near my house, catching me completely my surprise and slamming my face and right hand into the pavement. The most expensive bit was scratching my main glasses and needing completely new lenses.
It was my own fault. There is a woman who walks her dogs near me, with a permanent scowl and always complaining at the dogs. I was too busy looking at her and wondering if she had ever been happy when...bang. To her credit she did stop to check I was okay.