Engine stop running and it would not start running again

I was driving my Dodge Ram Van 1998 with only 128000 miles on it and suddenly when I was aproaching a red traffic light the motor stalled( it did turn off) I did check the fuel, plenty fuel, the power on the battery strong, the starter doing the job good cranking strong but the motor would not start and after trying diferent things; I had to get a tow truck and towe it home, what could possibly be the cause of it??? It was running strong and never gave me any problem, it has no leaks of any kind and it looks good in general but I dont know what it is,I will apreciate any ideas tha would help me find the problem, somebody toldme it could be the timing belt but I dont even know if my van even have one??; since it has the big serpentine belt wich I replaced not too long ago, if that could be the cause can somebody tellme how to test that before I start dissassemblyng anything?? Or if you know what do you think it is?? thank you, thank you guys.