falling like dominoes; domino effect
Describes people or things falling one after another in a chain reaction, often in crowds or accidents. The image is of shogi pieces lined up and toppling sequentially.
A domino-like fall occurred on the crowded train.
Please move slowly so that no one falls like dominoes.
toppling shogi pieces
Original meaning: the act of knocking over shogi pieces that have been stood in a row. Now mostly used figuratively; the literal sense is rare outside shogi contexts.
As a child, I lined up shogi pieces and played at knocking them over.
The crowd fell like dominoes, and many people were injured.
A domino-effect accident occurred on the station stairs.