ABC News' Melissa Lustrin and Michael Orr report:

After a yellow cab jumped the curb in New York City and severed the leg of a pedestrian, Dr. Mehmet Oz rushed to the scene to help first responders and a good Samaritan who were already helping the injured woman.

The accident occurred Tuesday morning around 11 a.m. outside Rockefeller Center in Manhattan, where Oz tapes his syndicated talk show, "The Dr. Oz Show." A British tourist was on the sidewalk when the cab stuck her and severed her leg.

David Justino, 44, a plumber, rushed to the woman's aid and made a tourniquet from his belt before he got some unexpected help.

"I was down there holding it and I felt somebody nudge me and I was a little angry and I said 'I'm waiting for a doctor,'" Justino told ABC News station WABC-TV. "And I heard, 'I'm Dr. Oz,' and I went, 'You're Dr. Oz?' I said what should I do, and he said, 'You're doing it.'"

The celebrity doctor later posted a photo with Justino on his official Facebook page, praising him and the first responders for their quick thinking.

"I applaud the quick thinking and heroic actions of David and the first responders. My prayers are with the victim for a speedy recovery," Oz wrote.

Another victim suffered minor injuries and refused treatment.

Police questioned the driver, 24-year-old Mohammad Himon, for more than an hour, WABC reported. He was finally released after being given three summonses.

The tourist, identified as Sian Green, was in surgery as of Tuesday night, according to WABC.

For Oz, this isn't the first time he has had to come to the rescue at a rather unusual time. The TV doctor helped a man Saturday who collapsed next to him after finishing a 5-K run in Utah.

Dr. Mehmet Oz/Facebook