The theater restaurant was closed because there was a serious leak in a pipe and the kitchen was flooded.

leak 是名词，意思是"泄漏"，指液体或气体从管道、容器等不该流出的地方漏出。 flooded 是动词 flood 的过去分词形式，flood 本意是"洪水"，作为动词表示"淹没、使泛滥"。flooded 在这里表示厨房"被水淹没"的状态。