I already experience this before but not in an important event. Me and my friends are doing some photo shoot on the street in one of festival here in our place. It was a whole day festival and of course the camera is use all day long. Don some shots after shots after shot and suddenly there was an error "Card cannot be accessed". The SD Card was fried and all the photos are gone. I used Canon 70D DSLR Camera.

If I think I'll excessive use the camera, I'll bring with me 2 cameras (I still have my old Canon 500D DSLR camera) so that I can alternately use them.