CHICAGO (CBS) — Metra passengers have been sitting on a stalled train for more than two hours, after the engine broke down on the way from the southwest suburbs to Union Station.

The Metra Heritage Corridor train was due to arrive at Union Station at 8:12 a.m., but started experiencing engine trouble about half an hour after leaving Joliet shortly after 7 a.m.

A Metra spokesperson said the train “was having a hard time getting up to track speed,” prompting Metra to notify passengers the train would be delayed. Ultimately, the engine stopped working altogether near 36th and Archer in Chicago.

Metra sent a “rescue engine” to tow the train into Union Station. That engine arrived shortly before 11 a.m. and hitched up to the stalled train, but it was unclear when the train would arrive at Union Station.