A couple weeks ago, Christopher Knafelc got a ticket for smoking on a subway platform because the Pittsburgh native had only been in the city a few months and didn't know it was illegal.

Today, SEPTA's police chief called the 32-year-old a "hero" and "what Philadelphia is all about" as Knafelc sat listening in the chief's office.

Knafelc jumped on the tracks at 12:40 p.m. this afternoon at Cecil B. Moore station along the Broad Street line when he saw another man stumble, then fall onto the tracks six feet below.

"Out of the corner of my eye, I saw a body flail on the tracks," he said about his first reaction. "I was 99.9 percent positive I wouldn't be electrocuted. ... So I jumped down."

He was the only one of about a dozen people on the platform to make that jump. Another commuter did tell a nearby cashier, who in turn called in to SEPTA's command center and had all southbound trains stopped, SEPTA police Chief Thomas Nestel III said.

"Trains at that time were coming every seven minutes," Nestel said. "And by the look of the platform, a train could have come at any moment."

The victim, who appears in the surveillance video to be unaware how close he is to the platform edge before stumbling over, is a 63-year-old man from North Philadelphia. Police said he suffered minor injuries from the fall and was at a nearby hospital with "complaints of pain."

Knafelc, who moved to South Philadelphia about six months ago, is on what he called court-order disability and is currently receiving psychological treatment.

He said he's made some bad choices in his life, but "I know I'm a good person."

"I can't imagine not helping someone in that position," Knafelc said.

He also said it was by happenstance that he was on the platform to be in a place to react bravely and swiftly.

"I deviated from my original plans [for the day]," he said. "I decided to check out Temple's campus because I had never been there before."

Firefighters arrived within nine minutes to pull still unidentified victim from the tracks. By 1:02 p.m. — 22 minutes after the man fell onto the tracks — he was being taken to a hospital, according to the surveillance footage.