A Young Man's Power Wheelchair Gets Caught on the Grill of a Semi!

I had to re-read this story several times before I could actually believe it. What I simply am confused about is how the young man's wheelchair got entangled in the semi's grill? Did he turn too closely to the truck? Did he miscalculate and back up too far? I am just uncertain how something like this could happen. What is truly miraculous is that the fellow survived! These wheelchairs, these contraptions that give mobility challenged individuals like myself their freedom, are strong in some ways, but over-all they are fragile and delicate. To have an electric wheelchair stand up to this sort of treatment, especially 50 mph!, is simply a miracle.