Two freight trains collided Wednesday morning, causing eight cars to derail near Interstate 84 near the mouth of Weber Canyon. About 9:30 a.m., one train struck the rear of the other, something being called unusual. Two cars spilled their load of grain and fell from the tracks above almost to the interstate below. One lane of westbound I-84 was closed for clean-up efforts, which could halt rail traffic for several days. Several crews including hazmat and a U.P. team were on scene to clean the grain, debris and diesel fuel. Several Union Pacific employees sustained minor injuries and were treated at the scene. The cause of the accident is still under investigation.