No one expected to meet with such sudden disaster.
Tips
history
Drawn from 《后汉书·周荣传》: 若卒遇飞祸，无得殡敛 — warning about 'flying disasters' that might overtake the unlucky without warning. The four-character form 飞来横祸 solidified in later vernacular fiction.
usage
横 here reads hèng (4th tone), meaning 'unexpected, unreasonable' — not héng ('horizontal'). Almost always pairs with 遭, 遇, 碰上. Close kin: 天降横祸 (disaster falling from the sky).
