( CNN ) -- Four people died when a school bus collided with a tractor-trailer at an intersection in Nebraska 's rural Webster County on Wednesday , the sheriff 's department said . Both drivers were both killed as well as two passengers on the bus , Webster County Sheriff Troy R. Schmitz said . The sheriff 's department did not immediately say whether any of the victims were children . The accident occurred at the intersection of County Road 1800 and Country Road R outside the town of Blue Hill , near the Nebraska-Kansas state line , Schmitz told CNN affiliate KHGI . The accident occurred between 4:30 p.m. and 4:45 p.m. local time , he said . Schmitz declined to release details about the accident , citing a pending investigation . How safe are school buses ?
A school bus and a tractor-trailer collided near Blue Hill , Nebraska , the sheriff says . Both drivers have been killed , he says . Also killed were two passengers on the school bus , he says .