On November 30, 2007, an Amtrak train crashed into the back of a freight train on Chicago South' side, injuring over 50 people. According to National Transportation Safety Board investigators, the train was traveling 25 MPH faster than the track warning signal allowed. The agency is investigating why the train operating engineer did not or could not obey the warning signal. Part of its investigation has involved interviewing witnesses, including the operating engineer, and gathering other at the scene.

The NTSB is the federal agency responsible for investigating major transportation accidents including railroad accidents, aviation accidents, marine accidents, and major highway accidents. With this train accident, "[t]he signal event recorders have confirmed a restricting signal… limited the train to operate at a speed not exceeding 15 MPH," said NTSB vice chairman Robert Sumwalt. Having completed its on site "field phase" investigation, the NTSB will continue the remainder of investigation in Washington D.C.

Though Sumwalt would not state human error was to blame, he did say the engineer' account of the crash and the signal recorder do match. The Amtrak train skidded 400 to 500 feet after the engineer applied the brakes. Whether the crash could have been avoided if train had been traveling within the 15 MPH speed restriction will be an important part of the investigation. Regardless, there is little doubt the high speed increased the severity of the impact and resulting injuries sustained by those on the train at the time of the crash.