Amtrak says train service on its Borealis passenger rail line between St. Paul to Chicago will resume in part on Thursday, and in full on Friday, after being temporarily replaced with buses.

In a later update, Amtrak said that Train 1333 will operate without the need for bus substitution on Thursday and Train 1340 will be restored without bus substitutions on Friday.

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.