Celebrity television host Dr. Oz was among those who rushed to help Tuesday when a cab jumped a curb and injured two people in a busy area of New York City.
A bicyclist and a pedestrian were struck in the accident that happened around midday at 49th Street and Sixth Avenue, near Radio City Music Hall.
One of the victims, a tourist, is now in critical condition at the hospital, and reports are that doctors were not able to save her leg. The other victim was not seriously hurt.
SLIDESHOW: Crash Scene Images
Oz said emergency medical crews were already treating the woman with the leg wound when he got there The studio where he tapes his syndicated talk show is nearby.
The doctor went on to credit a plumber named Dave, a Good Samaritan who had been walking along the street, with saving the victim's life by making a tourniquet for the woman.
"There was a dog leash and a belt – amazingly two mundane things you wouldn't think of, but they saved her life," Dr. Oz told reporters, noting that they helped to stop the bleeding.
A hot dog vendor reportedly helped pack the woman's severed leg with ice to transport to the hospital, FOX 5 in New York says.
The cause of the crash is still under investigation.