About 7:34 a.m ., central daylight time, on Thursday, September 21, 1989, a westbound school bus with 81 students operated by the Mission Consolidated Independent School District, Mission, Texas, and a northbound delivery truck operated by the Valley Coca-Cola Bottling Company, McAllen, Texas, collided at Bryan Road and Farm to Market Road Number 676 (FM 676) in Alton, Texas.
After the collision, the truck came to rest facing west on he right shoulder of FM 676. The school bus continued in a northwest direction and dropped approximately 24 feet into a caliche pit (excavation pit) partially filled with water, located in the northwest corner of the intersection. The bus came to rest on its left side facing southeast, totally submerged in approximately 10 feet of water, approximately 35 feet from the nearest shoreline. The bus front boarding door was jammed shut, but the rear emergency exit door was operable. No other emergency exits were on the bus.
Nineteen students died at the accident scene, and two died later in the hospital. The 21 fatalities were the result of drowning or complications related to the submersion. Furthermore, 3 students sustained serious injuries, 46 others sustained minor injuries, and 11 students were not injured.