In a negligence case (as most truck accident cases are), you must prove four facts to win: The defendant owed you a duty of care. This is easy to prove since all drivers have this duty. The defendant breached his duty of care. He may have violated a traffic law, for example, followed you too closely, or violated a trucking regulation. The defendant’s breach of duty was a substantial cause of the accident. You suffered personal injury and/or property damages as a result of the trucker’s breach of duty.