Hey mOOn,
I wish I had seen this earlier. Your woofer was undoubtedly damaged with too much power, like Ray said. The melted voice coil has frozen the diaphragm, like Ray said. It can be repaired by reconing (replacing the cone, voice coil, voice coil former spider and cone suspension as a unit). Klipsch used to recone the driver for you for about $75 and test the results. That's what I'd do.
If the other drivers are working, they will be fine. If you want to be anal-retentive, have both woofers reconed. The K-33-E and K-33 are made by Eminence. I have never found any reason for the change in designation. A good repair station can properly recone the driver IF they use the correct kit from Eminence. The part number will be a silver ink stamp on the back of the cone.
This is not a fatal problem and overhauling every driver will only cost about $75 or so each. After the overhauls, all drivers will be as perfect as new, even though only one needs it.
It will not hurt to replace the wiring in your Belles, though it may not help.