He made a quick step back to get out of the way, and a rock rolled under his feet.

It was as if the thousand yards of earth, and rock above them had rolled back.

In its wake several small rocks rolled down and came to rest at the boys' feet.

The rock rolled across to the far wall, bounced once more, and lay still.

The heavy rock that crashed it had rolled a few feet away.

His hands fell away, and he scrambled to rise, rocks rolling all about.

A rock rolled behind him and he jumped, turning swiftly, gun in hand.

His legs were crossed when a rock rolled under his feet.

With a cumulative roar, mud, water and rock rolled down into the lake.

The loose stuff did not travel far, but the original balanced rock bounced and rolled for some distance before it came to rest.