Wear your helmets kiddos!
Had a bike accident Monday. I was going downhill and tucked in an aero position. I hit a small bump and my air horn fell off the handlebars. Except it didn't just fall on the ground - it's connected to an air canister,so it was dangling and I was afraid it was going to get stuck in my front wheel and cause me to flip over my handlebars. So I slammed the brakes. Except I slammed the front brakes too hard (and remember I'm already leaning forward, going downhill) and I flipped over the handlebars. I estimate I was going 15-18 mph (I saw 12 on my bike computer a couple seconds before).
Helmet took the brunt of the damage. I walked away with no broken bones, internal bleeding, or even a concussion. I just have a sore back, some minor road rash, a bruised elbow, and a cut on my face (I think it's from the plastic retention mechanism from my helmet).
I am quite lucky to have no long lasting effects from this accident.
Incidentally some bike helmet manufacturers, including Bell, will give you a discount on a new helmet if you send in your broken one (they want to collect data on how their helmets fare in accidents).