UPDATED 06/13/11 11:20 a.m.

CHICAGO (CBS) — The Metra Union Pacific West Line had no trains running for part of Monday morning because there simply weren’t enough engineers to go around.

Metra confirmed that six Union Pacific West trains were canceled Monday morning — four inbound and two outbound.

WBBM Newsradio 780’s Mike Krauser reports commuters at stations on the heard a message on the loudspeakers that trains were canceled and delayed due to “equipment problems.”

LISTEN: Newsradio 780’s Mike Krauser reports

As of 7:15 a.m., there were no trains running on the Union Pacific West Line at all. Later in the morning, trains were running, but very slowly, as they had to make extra stops to make up for the trains that did not run.

Despite that, as of just before 8 a.m., CBS 2’s Susanna Song reported the scheduling boards at the Ogilvie Transportation Center said trains were running on time.

Metra spokeswoman Judy Pardonnet predicted the line would be shut down until midday Monday, and would be operating for the afternoon rush hour.

Pardonnet said the shutdown had to do with manpower issues due to unexpected absences by engineers.

Metra officials say they are in communication with Union Pacific workers about solving the manpower issue to move forward.

Both Pardonnet and Union Pacific spokesman Mark Davis say despite earlier discussion, the engineer absences are not labor-related. Rather, Davis said, a combination of vacations, family leave, training and sickness left several engineers with the day off at once.

“We’re working to get engineers to handle the West line trains as quickly as we can. I definitely want to stress this is not a labor incident of any kind,” Davis said.

He said the railroad even exhausted the manpower of fill-in engineers Monday.

Passengers coming into Ogilvie Monday morning said they were running about 60 to 70 minutes late.

“It is a little bit (frustrating), but it’s expected, and most employers know that if you take public transportation that things happen occasionally,” said Stephanie Amacher of Lombard.

The volume of commuters on the train that did finally leave was vastly more than usual.

“There had to be about quadruple the normal size that we have on the 6:43 train, so a lot of people were questioning what was going on,” said Dave Thompson. “We’re hearing this for the first time like you are.”

Thompson said he was glad he finally got on, but: “Now I’m just worried about going home. All of us need to get home, so I hope this is over with real soon.”

Davis said Union Pacific is working to get engineers that usually run other lines that are also qualified to operate the to substitute for the afternoon.

Davis added that they are working with crew management to see what happened and to make sure it would not happen in the future.

Watch & Listen LIVE