Contractor walked away from this job after running out of money

My parents hired a contractor to build their dream dock. The contractor said he needed the rest of the money to finish the project. After my parents paid him in full, over 100 thousand dollars, he barely showed up for weeks. He finally admitted he ran out of money and needed another 30 thousand dollars to finish. After being lied to my parents refused to give him any more money. My momma will have her dock even if I have to finish it myself.