December 18, 1950
Los Angeles, California
A photo shows a rig used for carbon monoxide poisoning, moving the car’s exhaust into the sealed cabin

This method of suicide and accidental death was more prevalent before catalytic converters and air-quality regulations became more common. The amount of carbon monoxide emissions has been reduced by 99%, and the presence of unburned gasoline in the exhaust makes breathing more difficult before the victim falls unconscious, leading those looking for a painless suicide to seek alternate means and those who would have succumbed to the exhaust accidentally to become aware of the danger of possible suffocation.