In 1966, Josef Papp (sometimes referred to as Joseph Papp or Joseph Papf) supposedly developed an alternative car engine that used inert gases. He gained a few investors but when the engine was publicly demonstrated, an explosion killed one of the observers and injured two others. Papp blamed the accident on interference by physicist Richard Feynman, who later shared his observations in an article in "Laser", the journal of the Southern Californian Skeptics. Papp continued to accept money but never demonstrated another engine.