Supercross is a dangerous sport. In fact, all motor sport is dangerous, regardless of the machine used and the health and safety rules instituted.
A fact that Trey Canard and Ryan Morais could attest to, having been involved in a nasty crash during the 20-lap main event of the Monster Energy AMA Supercross Series held at Dodger Stadium
Both riders came away badly injured; Morais with three fractured vertebrae in his neck, a broken jaw, and a bad concussion, Canard with two fractured vertebrae in his spine, and a bad concussion.
The thing to remember is crashes are a part of motor sports. Remove the risk of anyone coming a cropper and you take away the thrilling aspect of the sports. Everyone involved knows the risks and takes part regardless.