After Hurricane Andrew, my father and I needed to siphon gasoline from one of our cars to use in our generator. Lacking a proper container, we siphoned the gas into a 5 gallon plastic water cooler bottle. The gasoline promptly ate through the bottle's seam and spilled out, dissolving a good size chunk of our asphalt driveway. Lesson learned: use only approved storage containers for gasoline.
Diesel is extremely dangerous stuff. I nearly blew myself up a few years ago by not cleaning out a diesel tank with detergent properly that I was welding. Diesel residue vapourised and went boom. Fortunately there wasn't enough in it to create a large explosion but it required new underpants.
To add to that, my only car accident was due to having diesel on my shoes. My foot slipped off the brake and I rear ended some poor guy.