A small design flaw in my ore express minecart.
See I make a precision engineered express ore elevator in most forts since minecarts were added. They are basically a minecart track consisting of nothing but downward slopes to get ore from the excavation level to the forge levels as fast as dwarvenly possible. The hauler even takes a ride inside it so that when the cart reaches it's destination he can immediately push it back up for reset. They are beautiful examples of poetry in motion with only a minimal amount of animal blood spatter.
That was before I hadn't played DF for 2 months.
This time I built it from memory but seem to have forgotten that even a 1 tile long stretch of flat track spells death. I was reminded when the minecart used a one tile long stretch of flat track as an excuse to become airborne at the next downward ramp, and then hit the wall ejecting the hauler and all the ore. The hauler then hit the ground hard, then was hit hard again by 4 chunks of ore, a sandbag, and the minecart which somehow ended up above him, landed on him, and then RAN HIM OVER, as it decided to ignore that little hitch and continue on merrily down the track empty, jumping the track at the forge level, fly through the forge room, somehow not hitting anyone, and plunging into the magma cistern never to be seen again.
I'm not sure if the hauler is lucky to have avoided certain doom, or unlucky to still be able to feel all the broken limbs.