[user104658]

Not so much the wiring (if the appliance exploded) my question would be how did it spread so easily and quickly from the kitchen? They’re supposed to be designed and built with materials that make it easy for fire to be contained. For a lot longer than 90 seconds anyway. When I was a little Toy Chef the kitchen I worked in was essentially made entirely out of stainless steel, so it was basically impossible for a localised fire to spread. No fuel sources to spread on. And in my time I set fire to both a chargrill and an entire array if four deep fat fryers (that one was pretty scary tbh).