Katie Couric Pranks James Corden With One SERIOUS Fall Down The Stairs! See The Dangerous April Fools Day Joke HERE!

James Corden seems like such a sweet guy… just the perfect mark for an April Fools Day prank!
[ Video: David Beckham & James Corden Spoof Serious Underwear Ads! ]
And Katie Couric wasn’t taking any prisoners with this one!
She fooled James AND his entire Late Late Show audience with a fake fall down the stairs!
See the newswoman take a break from being serious — and risk a serious break! — in the silly but suspenseful clip (below)!