The Serpentine Belt Tensioner Pulley froze up and the beltbroke.
How to replace a Serpentine Belt Tensioner Pulley on 2003 Chevrolet Monte Carlo
there should be one bolt holding the tensioner just take the bolt out and the tensioner should come off
had to take out a lot of bolts, wasn't as easy as you make it sound and yes it is fixed no thanks to your response.
Those are a bear to do on the 3.8L engines. Glad you got it fixed. Please, for your sake, tell me you replaced the 2 plastic elbows for the cooling system? If not, don't be surprised if you have a coolant leak very soon. Email me at ChevyASE@aol.com if you need further help.