97 problem with power steering/AC/battery

My car was running fine and as I pulled into a parking lot last night all of a sudden I had no power steering. I immediately parked and the car sat over night before I tried driving it again this morning. I drove it less than a mile and my battery light came on. I also noticed that my AC wasn't cooling. When I got my vehicle home I parked it and opened the hood while the car was running. The belt that is attached to the alternator was not turning. I know very little about cars, I'm just curious to see if anyone has any suggestion as to what I might be looking at. Thanks for any suggestions.

So after looking at my car again and checking on the belt that runs the alternator/power steering pump/ac compressor I found that the main pulley that comes off the crankshaft of the engine had became loose and actually unconnected from the engine. I simply had to pull on the belt and the entire belt came out and the pulley dropped down and I just pulled it out by hand as well. Is this a common problem?