At approximately 2239, LACoFD and CHP responded to reports of an overturned semi truck with persons trapped inside I5NB, SO Parker Road. Arriving units found a box truck, on its side, blocking multiple lanes, with the driver out of the vehicle. The box truck was carrying approximately 16,000 pounds of solar panels. The driver was transported to a local hospital in fair condition. CHP issued a sigalert for about 3 hours due to spilled fuel in lanes. Only the right lane was open. CHP Newhall is handling the investigation.