By Mike Puccinelli

CHICAGO (CBS) — It’s been a chaotic morning for many commuters, as the extreme cold has caused trouble for public transit trains.

The South Shore Line suspended all service on Wednesday, and Metra suspended service on the Electric Line, due to problems with the lines that power the trains.

A Metra Heritage Corridor train between Joliet and Union Station also was delayed for more than an hour, after the extreme cold damaged the tracks. The train stopped near southwest suburban Summit while crews fixed the track, after sensors detected a break in the rails.

“There’s a break in the rail, and when that happens, the signal system sends electrical signals through the rail. When there’s a break, the whole signal system goes dark. As a failsafe, you don’t want a train operating over a broken rail,” Metra spokesman Michael Gillis said.

Engineers could not move the train to another track, because a freight train was in the way.

Passengers said there were fewer than 20 people on board at the time. The train was delayed about 90 minutes before it was able to move again.

Metra said problems are to be expected in such brutal cold. Passengers were pretty understanding.

“It’s like 20 below, so it’s kind of expected really. But we made it,” one commuter said. “A little slower than normal.”

Several other Metra lines reported delays Wednesday morning, mostly for weather-related problems.

The CTA also reduced schedules Wednesday for the Red, Blue, Green and Yellow lines due to the extreme cold. However, the agency said it has relatively minor delays in the morning and expects a smooth evening commute. Employees will be working day and night to keep the system running.

Mike Puccinelli