Before you go to shop if not already, you can grab all the pulleys shown below to be sure all turn. The AC, Alternator, Ps, water pump etc. Be sure all spin by hand with no noise. If you were using AC when belt broke, you could have compressor clutch going bad. just confirm everything spins by hand at least to know if you have a belt driven part that caused or not. A fairly clean break could? be defect belt as the belt is seamed together in one spot when made and maybe weak point. Lastly, the last shop may not have put on correctly meaning they may have been off one groove or so on a pulley. the belt tenisoner is last i can think of. maybe it went bad and belt became loose. Lost its tension. Below is a diagram of pulleys etc. Lets hope it is something simple.
A serpentine belt break is not coomon these days. 99% of the time something else caused it. Such as a belt driven item locking up. Alternators are the most common
ASE Certified Technician
32 years Foreign / Domestic Cars All aspects of Diag and Repair