Converse of subject

• block: Then, deep inside the cave, disaster strikes when their route back to the surface is blocked by a rockfall.

Adjective modifier

• massive: The other major development in the area was the massive rockfall at Beachy Head in Winter 1998/9.

• huge: WARNING: A huge rockfall has taken place ( July 2005?

• small: Debris from a small rockfall in Gage's Valley.

Modifies a noun

• event: We found that there was a dependence between low-frequency and rockfall events.