A taxicab trying to avoid a bicyclist in midtown Manhattan today, instead struck a British tourist - severing one leg and causing injuries to the other.

The accident immediately brought out the best in New York City, with many witnesses instantly coming to the woman's aide. "He hit the girl, she flew up in the air, her leg was severed right off ... so I just grabbed my belt, went over, lifted her up, put it on, held it," said David Justino, 44, a plumber working nearby.

Famed television personality and medical surgeon Dr. Oz also witnessed the accident from his midtown office - immediately rushing to the scene to offer his assistance.

"It was terrible," Oz told reporters. "The cab severed her leg. Thankfully, Dave had a belt, which everyone tugged on it. It was very smart thinking. A simple thing like a union plumber's belt can save your life - but anyone's belt can do it."

The tragedy is that - I don't know how the cab lost control - but this woman was devastated, and of course just trying to put her life back together is going to take a lot," he added.

The bicyclist involved in the accident told the NY Daily News that the cab cut him off.

“I told him to stop because I’m trying to go forward and people are crossing,” the cyclist said. “He loses his patience. He gets angry. He accelerates. Hits me.”

“I'm on the roof of a car like in a Steven Seagal movie, okay. And I’m on the sidewalk. I’m like this looking up at the sky.”

The 23-year-old woman was taken to the hospital and remains in critical condition.

Related on MNN:

Michael d'Estries ( @michaeldestries ) covers science, technology, art, and the beautiful, unusual corners of our incredible world.

Dr. Oz rushes to assist accident victim in NYC
Celebrity medical expert witnessed the accident, involving a tourist and an out-of-control taxi, from his office in New York City.