UNION - Hazardous material crews are working in southeast Nebraska today after a Union Pacific train derailment near the Otoe and Cass county border.

Emergency responders were notified Tuesday evening of the derailment about three miles south of Union. Radio traffic indicates that 22 cars ended on their side and a tanker slid into the nearby Wolf Creek.


Officials report that a synthetic rubber substance was spilled. The substance is the FDA-approved polyisobutylene, which is used in chewing gum and as an indirect food additive. 

The Cass County Sheriff's Office says the leak is partially contained by a natural dam about a quarter-mile downstream. The Murray Fire Department, one of several agencies to respond, provided booms to further contain the spill.

Cass County Emergency Management was on the scene Wednesday morning along with Union Pacific haz-mat teams.


A sheriff's office press release says the the derailment may have been caused by a thermal misalignment, which occurs when heat causes the rails to expand and push out of alignment.


Here is the sheriff's press release

Cass County Sheriff Robert Sorenson reported that on Tuesday, June 11, 2024, at 1610 hours, Cass County Deputies, along with Nehawka Fire, Cass County Emergency Management, Nebraska City Fire, and Otoe County Emergency Management, responded to a train derailment on the Union Pacific Railroad, just west of the intersection of U.S. Hwy 75 and Van Dorn St. Twenty-three cars of a northbound Union Pacific train derailed, with one car ending up in Wolf Creek. The derailment occurred about a quarter mile south of the Cass County/Otoe County line, with cars derailing in both counties and the front of the train stopping in Cass County.

Emergency crews discovered that a car loaded with polyisobutylene was leaking into a section of Wolf Creek in Otoe County. Polyisobutylene is a durable, flexible synthetic rubber used in products like adhesives, inner tubes, chewing gum, and fuel additives. The leak appeared partially contained by a natural dam approximately ¼ mile downstream at the county line. Polyisobutylene is generally classified as low in toxicity to humans and the environment under normal conditions.

Murray Fire responded and deployed booms (floating barriers) to help contain the spill and facilitate cleanup. No injuries were reported. The cause of the derailment is believed to be thermal misalignment, which occurs when heat causes the rails to expand and push out of alignment, according to the Union Pacific Police's interview with the train crew. HMR Hazardous Materials Response and Union Pacific Haz-Mat crews are managing the cleanup. The cleanup efforts are ongoing and it is unclear when the tracks will reopen.