The injured employee was helping a welder while a nearby trackhoe operator had a 4' pipe joint hooked up to the trackhoe with a strap. The operator leaned forward to adjust his side mirror and as he sat back down, his shirt was caught on the joystick, which caused the machine to move the 4' pipe forward. It struck the 6' main line pipe, which in turn fell off the cones and landed on the injured employee's legs. Both legs were broken and she was hospitalized.