Complex sentence: Alvin Carl Greene, Sr., and Johnnie Marie Cole--were killed in 1964 in a two-vehicle accident (they were hit by an 18-wheel truck doing 80 mph) on U.S.69, five miles south of Rusk, Texas.
Split into simpler sentences: Alvin Carl Greene, Sr., and Johnnie Marie Cole--were killed in 1964 in a two-vehicle accident. Their vehicle was hit by an 18-wheel truck doing 80 mph on U.S.69, five miles south of Rusk, Texas.