Please Help with 2002 Dodge Ram Van

I was driving my 2002 Dodge Ram Van home from work today with the check guages light came on. It showed the alternator quit working. I continued driving because i was only a few miles from home. Then truck started getting hot and the heater quit working. I had smoke coming from under the hood right as i pulled in. So I check under the hood and all the belts are on and working. Not sure if the alternator went out and is smoking the belts or I was overheating?? thanks for all the help.