Years ago when my CJ7 shorted and caught fire and burned up in my driveway one night, and when the volunteer fire cheif, who lived across the street and was on vacation at the time, but the firetruck which was still parked in his yard wouldn't start, and while the volunteer crew and I waited for another firetruck to arrive, while we watched my cherry red Jeep/bonfire as we could hear the siren in the distance... the old firetruck finally came rolling round the corner, sputtering like it was about out of gas, and then it backfired, and a four foot ball of flame shot out and rolled down the street behind it...
At the time, it wasn't very funny but now it kinda is.