An off-duty Transport Security Administration worker's daring act of heroism saved the life of a young Chicago woman who had fallen onto the tracks during a morning commute at Chicago's Avenue Blue Line station.

Eddie Palacios, 50, of Pilsen, jumped onto the tracks to stop the oncoming train after hearing people scream that a woman had fallen onto the inbound tracks shortly after 11 a.m. Wednesday.

"I looked over and saw a lady just yelling," Palacios told DNAinfo. "When I looked over, I actually thought it was a child who had fallen. They actually staggered three times trying to get up and get out of the way."

ABC News has been unable to reach him for comment.

Palacios, who was on his way to his job as a security checkpoint worker at Chicago's O'Hare Airport, immediately threw himself in front of the woman on the tracks hoping his bright orange hoodie would be visible to the train driver.

He frantically started waving his arms, which alerted the driver, who screeched the train to a halt just short of the platform.

The entire incident was caught on video by a DNAinfo reporter Jon Hansen, who was also waiting on the platform at the time.

(Photo Credit: DNAinfo.com)

Another passenger, Rita Sattler, yanked the unidentified woman up onto the platform by her hair. Patches of blood can be seen on the platform where the woman's scalp had been injured in the rescue.

"That man is really a hero," Sattler said of Palacios in the video. "I don't think I could have stood on the tracks."

The woman apparently told another commuter "I just slipped," and appeared to be leaving the scene by running up an escalator before she was stopped and taken by ambulance to a hospital.

Palacio, who joined the TSA just after the 9/11 World Trade Center attacks, credits his quick thinking to the various training courses he has taken at work in the past 12 years.

"I wasn't even thinking about putting myself in danger because I work at TSA. They taught us a lot of things to do and how to act in situations, not to put ourselves in harm or put other people in harm," he said.

TSA officials agree.

"Sometimes at checkpoints they have to make quick and calculated decisions," TSA spokesman Jim McKinney told ABC News. "Their training works."

While the woman was taken away for medical attention, Palacios quietly boarded a train and went on his way to work. He told his supervisor about the incident, but word quickly spread to colleagues of his deed by the end of the day.

"As long as I was feeling good that I did something, I didn't think anybody needed to know," Palacios told DNAinfo. "I didn't do it to brag about it or anything, because there was nothing to brag. I was just worried about the person more than anyone else.

"We're human, and we need each other," he said. "That's the bottom line. We really do."