already crossed into two other countries. Good to have you back. Thank you. And now, new video of the train crash in Chicago. ABC's Alex Perez walks us through the tape. And remember, the person... See More
already crossed into two other countries. Good to have you back. Thank you. And now, new video of the train crash in Chicago. ABC's Alex Perez walks us through the tape. And remember, the person driving had been working overtime, and had fallen asleep. Reporter: A terrifying moment captured on camera. This video appears to show a 3:00 A.M. Monday, as it barrels off the tracks onto a platform and up an escalator at the o'hare airport. Ntsb investigators say the operator of the train admits she fell asleep at the controls. She did not awake again until the train hit close to the end of the bumper. Reporter: Take a closer look. You can see the train approaching in the distance, standing nearby, a commuter and an officer chatting. In a panic, they run for safety. 32 people onboard the train suffering minor injuries. It kind of felt like somebody punched me. And then the lights went out. Reporter: It's not the first time. The same train operator was reprimanded back in February when she, quote, "Closed her eyes for a moment," and overshot a station stop. Reporter: The driver, who has not been identified, often worked overnight swing shifts. Tonight, authorities are trying to figure out why an automatic emergency brake system was activated but failed to stop the train. Alex Perez, ABC news, Chicago.
This transcript has been automatically generated and may not be 100% accurate.