I agree with Volvoscrapper to get a police report and report it to your insurance company. I would also suggest getting a written statement from the witness, if the police do not file a report. If your insurance drags its feet and the construction company is unresponsive then turn it over to your states insurance regulatory agency, I do not know what it is called in your state. Do not tell the companies you will file a report because it gives them time to prepare their case. The regulatory commission will launch an investigation and the contractor nor their insurance company wants to deal with such a situation. Your insurance company will also show a great deal more interest.

I also question the scrap yards involvement. Do they let multiple individuals unload at the same time, in the same area? If so, they be creating a much bigger liability issue than a damaged truck. In my yards, only one person is allowed to unload at a time in each area. It takes more time, but that way I only have to worry about my accidents, not those of everyone around me.