A driver believed to be an 18-year-old man died early Saturday after a single-vehicle crash near South Sam Houston Parkway West and South Post Oak Road, Houston police said.

Southwest Patrol officers responded around 3 a.m. An off-duty officer who was waiting at a traffic light told police the car was traveling about 80 mph as it crossed the intersection, then struck a pole.

The impact split the vehicle in two and ejected the driver.