I saw a biker going up the hill before her wipe out, so i'm thinking she was following that person but was going to fast coming down that hill. She probably hit the front brakes instead of back breaks and it caused her to flip off. Or the speed caused the front wheel to start shaking side to side violently and caused her to lose control. I fell like that many times just shake it off get back on and ride off. My friends and i set up 4 foot ramps to jump our bikes off of and crashed all the time. Little concrete scrapes and blood that we wiped off with dirt from the side of the road and got bike on the bike for more. These kids today, i just don't get it.