About 5:15 a.m. on November 30, 1983, a Trailways Lines, Inc., intercity bus traveling in the right lane of southbound U.S. 59 about 5 miles north of Livingston, Texas, struck the rear of an unloaded tractor-flatbed semitrailer operated by E.A. Holder, Inc. The bus then veered across the left southbound lane, crashed through a bridge guardrail and vaulted to a creekbank 26 feet below the bridge deck. It was dark, the weather was cloudy, and there was no roadside lighting. The pavement of the four-lane, divided highway was dry. The truck had turned right onto southbound U.S. 59 about 927 feet before the accident site and according to postaccident tests had accelerated to about 42 mph when ft was struck in the rear by the southbound bus. Six of the 11 bus passengers were killed; 5 bus passengers and the busdriver sustained moderate to severe injuries during the accident. The truckdriver later reported that he was injured.