Braided wire stuck to the cone,why...?

I can't explain what caused this.I was listening to music and all of suden my sub went dead,cheched the amp and sure enough my amps "protection" LED  was on,checked for shorts and all led to inside sub box,since it is bedind the amp rack i had to diassemble most of it,took the sub out and a black spot on back side of the cone sugesting that the braided wire touched the aluminum coated cone and actually was stuck on it with a few strands melted,what caused this ?,the sub is from ADS 10"and is their top series (rs.2),strange because i was not listening to it to loud and it's in a sealed box as per recomendations by the mnf.,it's only  about 5 months old...,do you guys think this is deffect covered by warranty,how common is this "shorting problem" ? if common at all.

Thank you.

Sounds like warranty to me. Send the ADS sub back to the dealer or shop and get a replacement one for it.