i have to side with doug on this issue. i also have never seen a fire in a refrig caused by a ammonia leak. most of the fires i seen have been from rodent nest near the burner,lp leaks, or shorts on the circuit board. i believe the circuit board shorts are causing the of the norcold problem.
the photos mostly show burnt wires on the elements, and burned circuit boards. when an element is run constantly, it will eventually burn the wires. especially when you have to deal with low voltage, fluctuations in voltage, like we all do in campgrounds.
because of websites like rv.net, and irv2, the norcold refrig fires are just getting the most attention. there are other fires that, because of not being norcold, are overlooked.