onfall

例句：

1. 1. The old building on the hill collapsed due to age and neglect.
   那座位于山丘上的老建筑因年久失修而倒塌。
2. 2. The earthquake caused widespread damage, including onfalls of buildings.
   地震导致广泛的破坏，包括建筑物的坍塌。
3. 3.The engineer carefully inspected the onfalls before deciding whether to repair or demolish them.
   工程师仔细检查了坍塌情况，然后决定是修复还是拆除它们。