At 6:30 pm a vehicle broke down in the northbound lanes of I -45 near Loop 336. Traffic behind is started to slow. That is when an 18-wheeler at a high speed slammed into the rear of a Toyota Four Runner and Chevrolet pickup. The impact drove the Toyota under another 18-wheeler. The Toyota driver was trapped. The striking 18-wheeler then went to the right lane striking a Ford Escape. The striking 18-wheeler was pinned in the cab. The female in the Chevrolet received minor injuries but was transported to the hospital. The driver of Escape was not injured and the driver of the other 18-wheeler suffered minor injuries. I-45 remains closed and will be until after midnight. The driver of the Toyota is in critical condition. It took two-wreckers and a skid steer to separate the 18-wheeler from the Toyota. They then had to load the engine of the Toyota which fell out.