Fifty years ago my mother bought a brand new trailer, had it moved to the reservation. We put all of our clothing and belongings in it and were waiting for the electricity and gas to be connected before moving in. 
One hour or so after the gas company left, the trailer exploded in flames and within a matter of seconds the entire structure was a fire ball. Had there been a fire department, not much they could have done, except stand by as we did and watch it burn. It was an inferno.
After the fire, very little was left. Everything inside  "melted" including the appliances. 
The smoke was 'toxic' due to the combination of the interior walls, flooring, and ceilings. 
I agree many of the trailers are death traps waiting to burn up or explode. I don't think there are any "new" trailers here(on our island), just ones from the '70's. I believe there are now very strict zoning regulations if located in the city they are subject to building codes/inspections. Living in a tent might be safer.