603 Crankshaft Pulley Failure

[MBDFahrer]

Well, its been a while since I've posted here, but I'm in dire need of advice. This year, I've been doing more long distance driving with my 603 than all other years. I've been down to Oceanside twice, and a trip to San Jose and back. Although I don't know what the exact cause is, but 2 days after the trip home from Thursday, the crankshaft pulley is busted. The symptoms included intermittent power steering failure, lights dimming, and overheating the engine with a #14 head.

So now the questions are:
What should I do?
What causes the pulley to fail in such a fashion?
How common is this failure?
What would be a ball park estimate on repairing/replacing the failed components?

At the moment, the belt is off, and not much else has been done. All the pulleys spin freely, so it seems nothing else has failed. The crankshaft pulley can also be spun by hand and also has some play.