Investigators say the drivers of a school bus and semi that crashed in southern Nebraska both contributed to the fatal collision. Investigators concluded both vehicles entered the intersection in rural Webster County at about the same time and both drivers had obstructed views. The September crash near Blue Hill killed the truck's driver, 21-year-old Travis Witte of Blue Hill and 59-year-old bus driver Marla Wentworth of Red Cloud. 18-year-old Dustin Tesdahl and 10-year-old Caroline Thallman, both students from Blue Hill, were also killed. 5 students were hurt.