1993 Buick Century serpentine belt broke, replaced and now

Hi I have a 93 buick century and my son was driving it when it happened so ill give info that I know. It was almost out of gas and he was going (to gas station which is real close) to put gas in it when the car died. He had no clue the belt had broke so continued to try and start it. Called me when it wouldnt start so I went to him (which was only a block or so away) and he said the belt broke. So we pushed it home and put a new belt on but now car wont start. With him tryin to start it belt looks fine on there but it just wont start. Could it have jumped time? Or should I be looking for something else? We put 3 gallons of gas in it with a gas can so it has enough to start but just turns over. Any idieas?