Given that I'm travelling to Chicago in a few weeks

This definitely caught my eye:

Blue Line derailment injures 32, train hits escalator at O'Hare

The operator reported to work at 8:40 p.m. Sunday. The 200-ton, eight-car train derailed at about 2:50 a.m. Monday. Blue Line run 141 hit with such speed and force that the lead car lifted at least three feet to the platform level while ripping out a bumping post, sheering off the front wheel carriage and flying almost to the top of the O'Hare station escalator.

"All the lights went out on the train. Lots of screaming. I knew something wasn't right," Dion Stokes, passenger, said.

A police officer and traveler saw the train coming and darted out of the way seconds before impact.

Indications are the operator, who was very tired, may have fallen asleep at the controls--she had done a lot of overtime recently. Thankfully injuries were not severe, no one died, and it happened in the wee hours of the morning, not rush hour. But I've been on that escalator before and it's unnerving to see a train on top of it. I'll be flying in and out of O'Hare, too. :) Scary.