The Daily News reports the events of the CTA "L"crash i February 1977. View Full Caption Creative Commons

CHICAGO — Forty years ago Saturday, the CTA suffered one of its darkest days as two "L" trains crashed at a turn in the Loop, knocking two rail cars off the elevated tracks to the ground and killing 11 people.

It happened Feb. 4, 1977, at the intersection of Lake and Wabash at the peak of rush hour — 5:25 p.m. More than 180 people were hurt.

Due to a reported "driver error," a Lake-Dan Ryan Line train plowed into the back of a Ravenswood train, sending four of the Lake-Dan Ryan cars tumbling off the elevated line at the turn, according to the Tribune.

Two of the rail cars hit the ground, while two hung between the street and tracks, the Tribune said.

The front page of the Sun-Times reported the CTA crash in February of 1977. View Full Caption Creative Commons

"It was horrible, just horrible," passenger Erica Williams told The Associated Press. "We were making a turn. The next thing I knew, I was falling forward. I heard a terrible noise, and that was it."

The driver of the Lake-Dan Ryan train, Stephen Martin, eventually was ruled responsible for the crash by the National Transportation Safety Board, the Tribune reported. Martin, 34 at the time and a CTA driver since 1969, "failed to heed a red signal" and was driving the train "at too high a speed when it crashed," the safety board said.

Joy Bivins, director of curatorial affairs at Chicago History Museum, says the accident "led the CTA to adopt very specific safety measures."

"The transit authority installed barrier girders on the four sharpest curves of the rail system; retrained train operations cited for moving violations; and began requiring its train operators to get permission from the control center before proceeding past a red signal 'on sight,' " she wrote in an email. "Also, the CTA conducted a fairly large safety study."

Ten years after the 1977 crash, 25 people were taken to hospitals after two CTA trains collided at the same curve, the Tribune reported.

Many of the 1977 crash survivors told the Tribune in 1987 they continued to ride the CTA, but had "minor psychological aftereffects."

Check out videos taken after the infamous 1977 accident: