This happened to my 95 back in 2001 with about 110k. Couple options for the actual repair. Easiest is weld it back on using somebody really good for confidence sake or replace that frame rail. After I had mine welded back together it took a long time to regain confidence in it. When it broke off on the highway it was an interesting ride until I got it stopped. I ran the truck to 215k turned it into a sledpuller and never had another problem. There are a handful of aftermarket options to help the trackbar in general. Do a search and see what you can find. There are 3rd gen convertions, lukes links and others. Other than mine, I haven't ever run in to anybody else that has had this happen. Good luck to your friend.
Thomas