He was on top of the structure. It's not very hard to believe that he could simply have been thrown free of the worst of it, with a few of the stones causing the damage visible in the background. In that case, everyone else would likely still be in the general vicinity of the body of the tower (which probably was mostly pancaked in the explosion; force goes down from the top, everything collapses). That would include most other people in it. As for his father, his different relative position to the explosion could have had different results. Actually, he probably flew farther, unless he developed a counterspell to keep him anthro.