A tractor-trailer driver whose semi crashed into a bus in Oklahoma and killed four members of the North Central Texas College softball team faces manslaughter charges.

Murray County prosecutors on Friday charged 53-year-old Russell Wayne Staley, of Saginaw, Texas, with four counts of first-degree manslaughter. Killed in the crash were 19-year-old Meagan Richardson of Wylie, Texas; 18-year-old Katelynn Woodlee of Windom, Texas; 20-year-old Jaiden Pelton of Telephone, Texas; and 20-year-old Brooke Deckard of Scurry, Texas.

Staley's attorney did not immediately return a phone call seeking comment on the charges. Staley previously told investigators he was distracted by something in his cab.

The team was returning to Gainesville, Texas, from Bethany on Sept. 26 when the northbound semi crossed the median on Interstate 35 and struck the southbound bus.