Eight people were injured shortly after noon Monday when a semi tractor trailer collided with an eastbound Max light rail train in Hillsboro. When firefighters from Hillsboro Fire and Rescue arrived, they found the front windshield of the front Max car smashed and moderate damage to the tractor portion of the semi. The accident blocked SE 10th and Washington Streets, a busy intersection for approximately an hour.Hillsboro firefighter/medics began triaging the patients at the scene and determined the driver of the semi and seven passengers on the train were complaining of various injuries. Five of the Max passengers and the semi driver were transported to area hospitals. A seventh Max passenger was transported by privately-owned vehicle to a hospital and the eighth person injured, also a Max passenger, refused treatment at the scene.Hillsboro Police and Tri-Met investigators are interviewing the drivers of the train and the semi, as well as checking the signaling system at 10th and Washington, to determine why the collision occurred.