The modern version of the waterbed was invented in 1971 but became a huge trend in the early 1980s, before people realized how bad sleeping on a plastic bag full of fluid is for you. Unlike regular mattresses, waterbeds can be seriously murderous. Take the case of Donald King of Stockton, California. In 1983, King bought a new waterbed and set it up in his bedroom with a hose leading into the input valve. He then fell asleep on the floor while he was waiting for it to fill up. The bed then over-filled, broke through its wooden frame, fell on top of him and suffocated him.