David Silverberg, a 66-year-old neurologist, said Friday he looked into the tunnel at the end of the platform to make sure a train wasn't approaching before he jumped down, making sure he didn't touch the rails.
"I heard people screaming and I looked down and I saw this figure lying between the tracks," he said.
"He was unconscious, not moving and without legs. Somebody was going to have to get him out. ... I knew the train wasn't going to be right on us. I was more concerned about the electricity down there."
Silverberg said it was a struggle to lift the man.
That's when he asked for help from a young man in a white shirt, who immediately jumped down and grabbed hold of the disabled man, whose face was cut and bleeding.
A security video of the rescue Tuesday shows people on the platform reaching out to pull the injured man to safety and then lending a hand when Silverberg and the younger man retrieve his motorized wheelchair.
Silverberg said the disabled man regained consciousness on the platform and did not appear to be seriously hurt.
"He told me he couldn't remember what had happened and that he must have passed out in some way," he said.
As emergency responders arrived at the scene, Silverberg said he realized that his new shirt, purchased for a neurology conference he was attending, was ruined.
"It was covered in black and blood, but that was OK," he said.
"It was a nice feeling that I had done something good for that day. ... I felt happy that I had come through and gotten away with it. It's risky to go down on the tracks."