I think there are a lot of posters here who have never lost a child due to an easily preventable accident.
Every other year we spring for tuition at a summer camp in New England. The boys go for 7 weeks of grand fun and independence. I miss them, but the growth in their independence is a joy, and it gives them a break from their protected suburban existence.
The overreaction pendulum swings both ways. On the one hand, you have kids tonning helmets, elbow and knee pads, and gloves to ride a Big Wheel; on the other, you have "I used to jump dirt bikes from to rooftop to rooftop, and other than a few fused vertebrae, nothin' bad ever happened to me!"
I never had a cast, a stitch or a hospital stay (I even still have my tonsils), but I had more or less permanent scabs on my elbows and knees from about the age of 8 to 13. Mom was less concerned about me hurting myself than ruining my clothes (not to mention the various forms of life I might bring home from the creek).
There's a balance to be struck here, and not just when it comes to injury. Hw are kids who live in an environment hosed down with anti-bacterial concoctions supposed to develop an immune response? I'm not saying that wounds shouldn't be treated or kids should play in the tuberculosis ward, of course, but it's healthy to get a little grubby.