What I expected to happen was to summon in a chest via falling sand entity,
what really happened was that when I tried this out on the latest snapshot, 14w25b, it caused my game to crash.

1. Put in a command block:

/summon FallingSandEntity ~ ~19 ~ {Time:1,TileID:54,DropItem:0}

2. Use any power source.
3. Should summon the chest down onto the command block, but instead causes a game crash.