ma-
For rocks to collapse, fall apart; for earth to erode; for earth to
slide down a mountain, i.e. a landslide.
Liminambo tang baka ong kahon amen animan napegnak.
The cow jumped over our rock fence around the field
therefore it collapsed.
Gapegnak da tang mga padir ong simban tenged
kaboay-boayan da ka.
The high rock wall around the church is already falling
apart
because it's been there so long already.
Napegnak tang bokid tenged nanlinog.
The mountainside slid
down (i.e. landslide) because of
the earthquake.
mag-
-en
To intentionally destroy, knock down a rock wall.
Pinegnak da tang mga soltiros tang padir ong
iskoilan.
The teenage boys knocked
down the rock wall at the school.