modern motorcycle helmets are designed to dissipate impact thru deformation and destruction of the shell. after such a horrific impact it is not unusual for the strap to give way. marco as with all top riders moto gp superbikes or even cars, they are pro's and do fully understand the danger so make every effort to properly use the best safety equipment available. this was a terrible accident resulting in the death of a truly talented rider who will be greatly missed......... R.I.P marco