Train traffic on the Union Pacific mainline in western Iowa is on hold following a train derailment in Carroll County. A Union Pacific spokesman says the accident occurred shortly after 5:00 p.m. about a mile east of Glidden. The Carroll County Sheriff’s Office arrived on scene at approximately 5:30 p.m. Initial reports from Union Pacific state around three dozen train cars are piled up at the site. Crossing in the area were temporarily closed but most are now open to vehicle traffic. Officials request that residents still avoid the area to allow clean-up crews easier access. The Glidden brush pile and dog park will be closed for the next several days to clear the route for Union Pacific response teams. The cause of the derailment remains under investigation. This is a developing story and Carroll Broadcasting will bring you more information once additional details become available.