In El Paso, Texas, a truck pulling a horse trailer collided with five parked cars, killing four racehorses, El Paso police said. The driver and two horses survived.

Police said they believed that a medical condition suffered by the driver, Ramon Rivera, 32, of San Elizario, may have contributed to the Saturday (Aug. 25) night accident on U.S. 54 about a mile south of the Texas-New Mexico border.

The truck swerved to the side of the road and hit the cars that were parked off the roadway. The trailer flipped onto its side, killing one horse instantly. Two horses were rescued. One horse had to be euthanized by a veterinarian, and two died as authorities tried to rescue them