I remember helping a neighbor in Brooklyn make some transfer tee shirts in his ground floor shop one day, he had a 1500 watt space heater plugged in and all I did was accidentally step on the extension cord which was laying on the floor and it shorted out under my shoe.
Here's another one- years ago I had one of those small cube shaped 1500 watt space heaters with the fan in it in my bedroom on low, one night the fan failed and I woke up to my dogs making noise and 4 feet from my bed was this flaming heater on fire!
I jumped out of bed, yanked the cord out of the wall socket and carrying it by the cord I threw it out the front door into the snow.
The whole thing was made out of plastic and it burned completely up, nothing but the metal fan, coils and screws left.
It was UL listed and all, just amazing they would even allow a 1500 watt space heater to be made with a PLASTIC case at all!
The fan had failed and it overheated.
After that I bought one of those all metal oil filled "radiators" and one of the all metal "milk house" heaters, no plastic ever!