at nearly 400 miles an hour. >> these are the first daylight pictures from the sight of what appears to be the worst single airline crash ever. a 747 has gone down. it's believed that all 524 people on board were killed. coming up next, investigators face together the grim task of piecing together the mystery. >> we had a catastrophic scene, we have millions of airplane parts scattered over the mountain side. >> but among the wreckage a miraculous discovery.