Ok...first thing...lower case letters...upper case means your yelling at us!
Its very likely that something locked up to break the belt(s) or they were so loose that they simply flew off or so old that they were dry rotted and broke. Take the broken belts to the parts store and tell them what make, model, engine you have and what you need. While the belts are off, check all the pulleys for any signs of possible trouble. Make sure they all spin freely and straight, you can even check the crank pulley by running the engine for a minute without the belts to see if the balancer is bad, but no longer than two! Then reinstall them in the proper sequence... you can tell where they go by lining up the pulleys from the side view. Back pulleys go on first...Tighten the accessories with a pry bar till there is a bit less than 1 inch of slack measured up and down when pushed with your finger for every 12inches of belt between two pulleys. DO NOT OVER TIGHTEN THE BELTS! Its better for them to be a bit loose than to be too tight. This is tricky to do by yourself because you have to maintain tension on the belt while tightening the bolt. So, dont be surprised if it takes a few trys.
Also, make sure that the belts sit properly in the pulley. It shoud be almost flush with the top of the pulley when tight. If its not, than its either too big or too small for the pulley. After installing all the belts, double check all your bolts to make sure they are tight. Crank engine and look at the belts as they go around the different pulleys. They shouldnt have much slack or flop around much. If they do, they are too loose and will need to be tightened up. Unless something major is broken, bent, loose or warped, you should be good to go. Good Luck!
Bill