There was a mechanic that I knew who filled a couple propane tanks and just put them in his trunk unsecured. He went to take them home and lit a cigarette as soon as he started his car. Yeah, he hadn't shut the valve on one of them fully, so the whole interior went up! He was able to pull the tanks out, saving his car. But he had third degree burns on his arm up to his elbow and was out of work for 3 months. Yeah, he was that kind of stupid.