I had tire go on the pulsar daily driver on the way back from Sydney a couple of months back.
When I asked my tire guy what caused such issues - without explaining any of the circumstances or my own thoughts - he said same as several of the responses above. One or more belts can break due to impact and once some are broken the others are placed under extra stress and break also. He suggested running higher than recommended pressures i.e. 40psi in my 185 14 inch pulsar tires to help as a lack of pressure is also a feature in such failures.

Cheers,
Jason