If there has been a break-out, someone has escaped from prison.
例句
A prisoner escaped one day after he was recaptured following a previous break-out...一名囚犯在前次越獄被抓回一天后再次逃脫。High Point prison had the highest number of breakouts of any jail in Britain.海波因特監獄在英國各監獄中越獄事件最多。