Conan O'Brien rushed to the hospital after hitting his head doing the taping of The Tonight Show

The bigger they are, the harder they fall.

NBC will be airing a repeat of The Tonight Show Friday after Conan O'Brien fell during a skit being taped for tonight's episode and was taken by ambulance to the hospital, the network confirmed to E! News.

"Last thing I remember I was enjoying the play with Mrs. Lincoln, and the next thing I knew I was in bed being served cookies and juice," O'Brien said afterward.

A source says O'Brien was running down a flight of stairs when he slipped and banged his head, possibly sustaining a concussion.

Teri Hatcher and Seth MacFarlane were tonight's scheduled guests.

We hope one of our favorite funnymen gets well soon!

(Originally published Sept. 25, 2009, at 7:14 p.m. PT)