Well, the theory is actually that the clipping causes a square wave, which has a lot of high frequency harmonics, not DC exactly, so more likely to blow a tweeter.
It can happen for a lot of reasons including age and prior abuse. There are two kind of failures. Mechanical and electrical.
Mechanical means that the surround or the spider has failed, either from age or excess physical motion. The electrical failures are caused by the melting of wires in the voice coil or to/from it or a disconnect.