Heading back to Ft. Lauderdale last Wednesday in my 94 325i I had a pretty bad experience. I had just gotten off 95 and onto the Turnpike in Jupiter when all the sudden I head something that sounds like I ran something over, but I knew I didn't hit anything. So I knew something was wrong, next thing I know the battery light comes on and the temp gauge goes straight to red. I had no power steering or power brakes, car was overheating like mad. Good thing I was able to get right off at the next exit and didn't have to pull over on the side of the road. I get to a gas station off PGA blvd. and sure enough I pop the hood, one fan blade missing, no serpentine belt or a/c belt and coolant everywhere. I guess either the fan blade broke off (has happened before) and ripped off the belts, or one of the pulleys seized causing the belt to break which broke the fan blade. The car overheated big time since the water pump had no power and the radiator had boiled over but at least everything else was ok and no major damage to the engine. Got my cousin to come pick me up after about 3 hours. Couldn't fix it there because it was like 11 pm all the parts stores were closed and the next day was Thanksgiving. So I just left it in a Publix parking lot until Friday, when I had to go to BMW and get a whole new pulley assembly and a v-belt and drive back up to Jupiter, drive the car up on a phone book so I could get under it and install the new pulley and belt. All in all, everything seems to be ok though, so I guess I lucked out the damage was minimal.
Oh, and big thanks to DuckyD for the "Need Help with your E36" thread , its the only place I could find the diagram for routing the serpentine belt, without it I would've been screwed, getting that thing on there would've been impossible if I tried to do it without it.