I had a KA which mysteriously blew up

they gave me another KA, with the same reg as the old one except the last letter was different, and i took a humpback bridge at 3 figure speeds and took out, landed, grounded out, smashed the sump, fishtailed, caught grip and rolled 3 or 4 times, looked like a triangle and i couldnt get out was trapped by my legs upside down for about 30 mins till someone came and all i could smell was petrol