땅이 꺼지다. Ground sink. *한숨만 땅이 꺼져라 쉬죠. ( a little correction :)) I don't know this expression is used in English, but if literally translated, the sentence would be "I sigh like ground is sinking." or "You know;I sigh like ground is sinking." It means he or she sighs with great anguish or with worry. For reference, "꺼져라." is a rude slang which means "F*ck off." when used alone, (asterisk for masking expletive :))

It's slang for "Go away" "Get lost!" "Beat it!" you could also say 꺼지다 or 꺼져.It can also mean "to be turned off" ie. My phone turned off.