Video: James Corden gets pranked brilliantly by big star on new show
James Corden thought Katie Couric had died on his show when she played an April Fool's prank on him.
The host of 'The Late Late Show' was welcoming the 58-year-old journalist onto the programme when she appeared to take a tumble down the stairs on her way to the stage.
Introducing Katie, James said: "And finally, she's a journalist, she's a best-selling author, the Yahoo! global news anchor. Go wild for Katie Couric."
The curtains opened to reveal Katie fiddling with her shoe before the horrified audience watched on to see her trip and fall head first down the set of stairs.
James then rushed over to her aid but his obvious panic was interrupted by the real Katie standing at the top of the stairs. She then told the worried host: "Up here James! April Fool's!"
When the pair were safely back in their seats, James admitted someone falling down the stairs was one of his worst nightmares.
He added: "I can't breathe. That's like our worst nightmare. That is so funny. That is an amazing prank...
"We've been talking about those stairs. We've been going back and forth. I was like, 'Oh my God. Katie Couric just died.'"
It will only add to James' nerves as he settles into his stint on the US talk show as he previously admitted he was on a "quest" not to vomit before going live on air.
He said: "All you can see is the spotlight from the back of the room on the curtain, just this circle, and you just go, 'Ah, this is going to open in a minute ... and I'm going to have to walk out there and look remotely like I know anything about anything.' And then it's just a quest to not throw up on your own clothes. That's the truth.''