__It happens. Sure it is scary and horrific, but it is aluminum that is 30 years old, and sometimes we forget we are riding on vintage stuff. I have a lot of parts on my bikes that were made before I was born, some were even manufactured before my father was born. It is good to inspect your components every once and a while. Make it a routine to clean your bike and make sure no hairline cracks or other defects developed. You will be left with assurance your parts are good and you will have a clean bike!
Moser Campagnolo Gran Sport crank arm,
Via Bicycle 