Infinity cone separated from surround.?

Today as I was commuting to school I heard rattling from my sub and way less bass than usual. When I got to school I checked it out and the cone had separated from the surround. I own an Infinity Reference 1060W 4-ohm rated at 275W RMS along with an alpine MRP-500 300W RMS amplifier. The sub is in a .75cu/ft box which is recommended in the manual. The temperature this morning was in the 50's so it couldn't have been heat. Does anyone have reasoning for this? Perhaps I had the gains set wrong and there was clipping. I loved the sub and only had it for 2 months and it sounded amazing. Should I try another one or go with a different brand? I don't know if it makes a difference but I mainly listen to metal/ death metal is it possible it just can't handle the bass drum speed? Thanks for the help.