That is certainly not good, and glad that the post-blowout subsequent body and tow dolly damage was not too bad. It would be good to get some axle weights, and then see how that compares to your tire rated load capacity. I agree with others, and would bet money, that you are very close to the max load on the front tires. Always good to have some margin, and if running at or even over the load limit, the result might be exactly what you experienced. I do believe that the 16 inch tires are undersized for adequate safety margin.
FWIW, I had a front tire catastrophic blowout on my MH, cruising at 70 mph. Definitely not a fun experience. I ended up like you buying a replacement without much options - mine has approx 400 miles on it. Ultimately I decided my tires were too close to max load and upgraded to a larger and higher load range tires on my front axle.
2005 Kenworth Showhauler truck conversion.
. 44 ft, Cummins ISX15 450 hp, 10 speed, twin screw
I used to have a handle on life, but it broke