godan verb (-ru)
begin to crumble; start collapsing
Describes the onset of crumbling or collapsing, often of structures, cliffs, or abstract things like relationships.
地震で壁が崩れかかっている。
The wall is starting to crumble due to the earthquake.
彼の計画は崩れかかっている。
His plan is beginning to fall apart.
godan verb (-ru)
crumble and fall onto; collapse onto
Emphasizes the direction of collapse onto another object or surface; often used with に or へ.
崖が崩れかかって道路に落ちた。
The cliff crumbled and fell onto the road.
古い屋根が崩れかかって庭に散らばった。
The old roof collapsed and scattered into the garden.