Amtrak blames Chicago Union Station delays on 'human error'

CHICAGO (AP) - Amtrak officials say "human error" was the cause of switch and signal problems that delayed tens of thousands of Chicago commuters during Thursday's evening rush hour.

Amtrak spokesman Marc Magliari said Friday that the railway analyzed what happened at Chicago's Union Station and found that the it was human error "in the process of deploying a server upgrade." The error happened at a technology facility that supports Amtrak's dispatch control system at Union Station.

The delays affected commuters who use the Metra rail system that also operates through Union Station. Magliari said dispatchers couldn't see the locations of the trains and the only way to safely move traffic was one train at a time.

Amtrak officials apologized and said they are taking steps to improve operations in Chicago.