There was a report in Russian Times that a worker had died while digging a ditch at the Fukushima disaster:
The operator of Japan’s crippled Fukushima nuclear plant, TEPCO, suspended the cleanup at the facility after one of the workers died while digging a ditch Friday….A man in his fifties was buried under gravel as he was digging near the nuclear plant’s storage area, Tokyo Electric Power Co. said.
This sounds like a land slide or a sink hole. It is well known that they have been added tons of water to keep the reactors cool. Enough water into soil makes so unstable land, and it is prone to collapse. This is the recipe for mud season, and has been discussed on this blog. . One would anticipate that this will be a common problem in the area around the Fukushima disaster.