The National Transportation Safety Board has deployed a team of investigators to the scene of Monday morning's head on collision between two trains on the CTA blue line that injured at least 48 commuters.
The collision happened at approximately 7:45 a.m. on Monday morning, during the busy morning rush hour at the ground-level Harlem Station in Forest Park west of Chicago, CTA spokeswoman Catherine Hosinski said.
Forest Park Mayor, Anthony Calderone said forty-eight people were transported to 10 area hospitals, adding that none of the injuries was life threatening.
"Most of the people were complaining of either neck pain or back pain," Calderone said.
Investigators say it is a mystery as to how the empty four car runaway train was able to leave the CTA rail yard and struck another Blue Line train at Forest Park near Harlem Avenue and the Eisenhower Expressway, officials said.
"To the best of our knowledge, from what we know right now, there was no driver, there was no human being on that eastbound train," Forest Park Mayor Anthony T. Calderone said.
A Chicago Transit Authority spokesperson appeared baffled, as he tried to explain that somehow, the “out-of-service” train left the yard and headed eastbound, traveling about 20 mph.
Robert Kelly, President of the union which represents train operators, said the moving train was apparently empty and safety mechanisms should have stopped it automatically before it entered the station.
"Right now it is starting to look like a mechanical malfunction," Kelly said.
CTA spokesman, Brian Steele called the collision an extremely rare occurrence and cited the very good safety record of the CTA system. Steele called Monday morning's train collision an aberration.
The National Transportation Safety Board (NTSB) team of investigators from Washington D.C., arrived at the scene of the train collision in Chicago on Monday afternoon.
Since 9/11, international and national security experts have repeatedly warned the U.S. Department of Homeland Security officials that trains are an attractive target for terrorists.
In dozens of recent studies and reports, including the findings of a 2010 GAO report, investigators warned that while additional resources have been dedicated to securing the nation's air transportation, America's ground transportation system, the trains and subway systems security remains inefficient and poorly coordinated "soft targets."
Forest Park Mayor, Anthony Calderone said police are treating the station where the trains collided as a crime scene as a precaution to preserve evidence, even though Forest Park police are not saying any crime had occurred.
Check back for updates.