A taxi jumped a curb Tuesday and plowed into an advertising kiosk and a shoeshine stand at a busy corner in downtown San Francisco, leaving the driver and two people in critical condition, authorities said.

The taxi driver and two people at the shoeshine stand were rushed to San Francisco General hospital with life-threatening injuries, police Officer Grace Gatpandan said.

The taxi jumped the curb in the Financial District.

"The cab came barreling down Market Street, hit the newspaper stand and then the next thing I saw was the old man flying over the shoeshine stand," Susan Giammona, who sells shawls and scarves near the crash site, told the San Francisco Chronicle.

Officials initially said the taxi had crashed into a public toilet but later said it hit an advertising kiosk.

Police were investigating what caused the accident and interviewing witnesses.