A spokesperson for Amtrak said in a statement to TMJ4 that they discovered corrosion in several Horizon railcars while working with manufacturers, which resulted in the removal of some equipment.

The passenger rail service said it is running buses for its Borealis route, which runs one train a day to and from Minnesota. Half of Amtrak's six daily Hiawatha trains to and from Milwaukee are also running on buses.

The Amtrak Borealis train between St. Paul and Chicago is being temporarily switched to a bus replacement service after workers discovered corrosion problems involving several train cars. A spokesperson with Amtrak tells Bring Me The News routine inspections also found corrosion on Horizon passenger cars on three other lines of service.