Quick! Get that child away from this ticking-time-bomb of a coal gas-powered bus! Seriously, this particular bus was modified with a huge balloon on the roof to hold a manufactured fuel from coal gasification. Thar she blows! Not only is the gaseous fuel stored on top of the car, it's stored in fabric. Does the word Hindenburg mean anything to you? Really, we wonder why this technology never took off.
[Source: Modern Mechanix blog via Treehugger]