A proverb meaning that misfortunes tend to come together — when someone is already down, more bad things happen (similar to 'when it rains, it pours' / 'a misfortune never comes alone').
弱り目に祟り目で、家の修理代までかさんでしまった。
With misfortunes piling up, even the house repair costs increased.
彼は失業して弱り目に祟り目だと言っていたが、すぐに仕事が見つかった。
He said misfortunes kept coming after he lost his job, but he soon found work.