to fall through the cracks ---------- 被遗漏（非正式）

英文释义
(INFORMAL) To be overlooked; to be unintentionally neglected. (NOTE: also, "to fall between the cracks").

例句
The people of the endangered town were warned of the coming disaster, but unfortunately a couple people living on small, almost hidden streets fell through the cracks, and did not hear the order to evacuate.
处于险境的城镇的居民接到了灾难将临的警告，但不幸的是，住在一条近乎隐密的小街道上的两人被遗漏了，没有听到疏散令。