by jorb » Thu Jan 28, 2016 12:56 am
The survey is most likely using the dirt to flatten some other part of its area.
I suspect that it is not a bug, thus.
"The psychological trials of dwellers in the last times will be equal to the physical trials of the martyrs. In order to face these trials we must be living in a different world."
-- Hieromonk Seraphim Rose