A driver flipped his car over railroad tracks on the South Side, then fled the scene and left his passenger behind, San Antonio police said.
Investigators believe the driver missed the turnaround under Loop 410 and Commercial, and instead went straight off the road.
Officers arrived at the scene and saw the passenger still inside, but the driver was nowhere to be found.
The passenger was taken to the hospital, but police did not know the extent of that person's injuries.
Police searched for the driver with their Blue Eagle helicopter, but did not find anyone.