An employee was working with a pump truck operator to retrieve a retrievable plug down the hole. They were flushing sand off of a retrievable bridge packer (RBP). The TIW valve was rigged up with a swivel joint to the pump truck hose when it came loose and fell from overhead. The TIW valve struck the employee in the head and shoulder causing him to fall over. The employee sustained head trauma, a broken shoulder blade, and injuries to his shoulder, arm, and elbow. The employee was hospitalized.