HOUSTON -

An 18-wheeler caught on fire Sunday morning, killing the driver and shutting down all lanes of a major Houston highway for most of the day.

Houston Fire Department officials said the 18-wheeler became engulfed in flames after the driver struck a retaining wall on 610 South Loop East.

Heavy smoke billowed up from the roadway where the South Loop meets with I-45, and both sides of the highway appeared to be burned after the flames were extinguished.

Investigators continue to work to find out what caused that accident.