"Go wild for Katie Couric!" James Corden shouted to the audience as the curtain was pulled back to reveal Couric tripping and rolling multiple times down a long set of stairs that guests typically walk down to enter the stage.

The band stops playing as Corden -- in shock -- drops obscenities while running to her aid.  Audience members try unsuccessfully to grab her as she rolls past them down the stairs.

Couric is face down on the floor when Corden finally gets to her.  Fortunately, Katie will suffer no lasting health issues from the fall.

Corden admits that the show's producers have previously had discussions about changing the set design, worried that someone could be hurt on the stairs.

Watch the shocking video here!