Definition
This idiom is used to express that when one unfortunate event occurs, it is often quickly followed by a series of other unfortunate events, making a difficult situation even worse.
禍不单行，败不连年
First, I missed my train, and then I discovered my wallet was stolen; it never rains but it pours.
首先，我错过了火车，然后发现我的钱包被偷了；真是祸不单行。
She lost her job, and then she was diagnosed with a serious illness; it never rains but it pours.
她失去了工作，然后被诊断出患有严重疾病；真是祸不单行。
Just when we thought things couldn't get any worse, the company announced layoffs. It never rains but it pours.
就在我们以为情况不会更糟时，公司宣布裁员。真是祸不单行。