I can think of two.
First of all, I have an intense fear of horses falling on me. I was riding a friends pony for her because she was sick and I didn't have a horse to ride. I was cantering him and began to do a 20m half circle between E and B. Around centerline, he just fell down. I fell onto his neck just as he got up and I just slid off and landed on my feet. I didn't really fall off, but it was close enough to scare me.
The second time I was riding out in my uncle's field. My grandpa was working on his truck and my mom was riding around 100 ft from me. I asked my horse to canter and he did, I turned him and he took off. I clamped down with my legs so he bucked and spun, sending me flying. I remember going to put my arms out then thinking that it was a bad idea and tucked them up against my chest. The next thing I remember is laying down, facing the opposite direction of which I had been going, my bridle about 6ft in front of me and my horse across the field. My grandpa came running over to me and got me to lay down flat. After my mom caught my horse, brought him back, and put his bridle back on I got back on (of course).
On our way home after riding I got a wicked head ache so we went to the ER just incase. I got x-rays of my head, neck and back. They wanted to take more but I had reached my max for the year . It turns out that I had a concussion and my Dad got in trouble for not calling the ambulance even though he wasn't there .
It's definitely not as bad as some stories posted on here but they are my examples.