“多亏” (duōkuī) can be translated as "thanks to" and is used to express that, due to somebody's help, a negative result has been averted. It is similar to 幸亏 but emphasizes a feeling of gratitude towards a specific person for the outcome, rather than attributing it purely to fortune. Often 了 is placed after it.

Structure 
多亏（了）+[source of help]

Examples