He was planning to add more, but his foot came down on a loose rock.
As Case came out with his men he grabbed a loose rock at the side of the opening.
Loose rock and snow fell towards us from our right.
A fall of loose rock warned me when he was about twenty feet away.
The body was on a dangerous slope of loose rock.
The mother reached down, picked up a loose rock, and stepped forward to do the same.
His horse stumbled on the loose rock and he went down.
Half way up, her foot slipped upon a loose, round rock.
Typically, loose rock and soil is placed over the top.
Some loose rock that had been traveling with the cloud was coming down.