The runaway train slammed into another train on Monday morning, causing minor injuries to dozens of people and halting the commute for hundreds. On Tuesday, Blue Line trains were using one track to pass by the still closed Harlem stop, where the runaway train wreckage remains under a tarp.
Shuttle buses are in place to move passengers around the Harlem stop."The biggest confusion is that we don't know where to catch the bus from. And all of us have to get going to work, so it's causing a little bit of frustration and a little bit of anxiety," Kristen Vogt, commuter, said.
It isn't clear how long the CTA's Blue Line Harlem station will be closed.
NTSB investigation continues
National Transportation Safety Board agents returned to the Harlem stop Tuesday. They spent much of the day interviewing CTA workers behind closed doors.
Investigators are looking into how the so-called ghost train left the CTA rail yard and traveled eastbound on the wrong side of the track to the Harlem stop, colliding with a stopped westbound train that was full of commuters.
"Either Casper the Ghost was driving the train, someone was operating it from possibly the third fourth or fifth cars or somebody with extensive knowledge sabotaged this train," said CTA Union President Robert Kelly.
Thirty-three people were treated for minor injuries.
"The first thing you check is that the signal system worked as it's designed-that's the first thing you want to rule out. Then you want to rule out mechanical issues. If it's not signal and not mechanical then you want to look at operations. Cause then it might be a human factor accident," NTSB railroad accident investigator Tim DePaepe said Monday.