崩落

1. Origins, structure, and basic meaning

• Structure: 崩落 (ほうらく) is an action noun for a cliff, ceiling, or similar mass collapsing and falling.
• Basic usage: 崖が崩落した reports a cliff collapse after heavy rain, while 天井の崩落を防ぐ makes a ceiling failure the event prevented through reinforcement.

2. Common pitfalls and similar expressions

• Occurred collapse and prevented failure
  • 崖が崩落する is an occurred event, whereas 崩落を防ぐ is action against a future one. The noun has a broader failure sense than a mere surface crack.