A New York City taxi jumped the curb on Tuesday (August 20) hitting a British tourist and severing her leg.

According to witnesses, the cab swerved while attempting to avoid hitting a cyclist and struck 23 year-old Sian Green.

Plumber Dave Justino who worked nearby removed his belt and made a tourniquet for the woman's leg before the paramedics arrived.

"The cab driver was just supposedly ran off the road by a bicyclist and he had no chance to step on the brake and he hit the girl, she flew up in the air, her leg was severed right off, the other was mangled so I just grabbed my belt, went over, lifted her up and held it," Justino said.

Surgeon and U.S. TV personality Dr. Mehmet Oz who has an office in the area rushed to the scene to help the victim.

"There was a dog leash and a belt, amazingly two mundane things you wouldn't think of, but they saved her life," Oz said.

Green was rushed to Bellevue hospital in critical condition with one leg severed below the knee and injuries to the other leg.

The cab driver, 24 year-old Faysal Kabir Mohammad Himon of Queens, was issued a summons for being an unauthorised driver and set free.

Presented by Adam Justice