I've visited the wreck of the 5037 out east of Gila Bend. The boiler got launched off the frame and landed on the track ahead of the little ALCO that was helping them up the hill. The boiler bounced and landed on the side of the right of way. To this day is there is a hole in the ground full of asbestos insulation. The ALCO fell into the hole and kept running until shut down by the rescue crew. The force of the blast knocked the rear wall of the switcher in about a foot and blew out all the glass along with the two crewmembers. I think 5 guys died in this deal. I've got a couple of firebricks from 5037's firebox that got blasted a couple of hundred feet into the desert. My buddy found an SP water can with one side caved in nearby.
I've never seen the shots of the 4430 in the ditch. Have any details on that one?
The only on the road boiler explosion I've ever head of on the narrow gauge was when 451 blew up leaving Shawano Tank on the west side of Marshall Pass in the early 1920's. The crew waiting for them up at the top was witness to the event. I've heard some folks found evidence on the hillside above the location. I spent a couple of hours wandering around, but probably was not in the right spot. The area had experienced a ground fire in the past and nothing was evident.
A 2-8-0 blew up in Durango because of a flaw in the boiler. The dome course ripped open with rather spectacular results.