You warned the general contractor that if he didn't properly secure the lines then it was likely things would fall. You warned him and he told you not to worry about it. Well, what you said would happen, happened. Someone on the crew was injured by a falling piece of equipment. Even if you work in a dangerous job like construction, you never expect to be injured. You have worked hundreds of jobs and put in thousands of hours. You are as comfortable on a construction site as you are at home.