96 GMC won't fire

I've got a 96 GMC with a 7.4L, 2wd, AT. Went to start it this morning. Fired once. Then nothing. Turns over fine. Can hear the fuel pump running. Sounds like there is no spark. Just happened this morning and I didn't really have time to investigate before work. But I thought I would ask you all what I should look for. I'll start with checking the OBDI setup to see if it tells me anything. Not sure where to go from there though. Truck has been running great all year. So this caught me off guard. At least it was still in my driveway!!