- At one point during the show, Andrew Keenan-Bolger (Crutchie) has a banner that says 'strike' attached to his crutch and says "You see this, Mr. Pulitzer?" One show he forgot to attach the sign  and went onstage without it, so when his line came he said "You see this, Mr. Pulitzer?" and did a crazy little dance

Here's the interview (copy and paste the link): 

Or this one, where he actually mimes the dance:  (he starts talking about it at 3:53)

_________________________________________________________

- During 'King of New York', Kara Lindsey (Katherine Plumber) is supposed to catch a broom and toss it back, but she accidentally whacked it and sent it flying into the pit orchestra and hit the conductor in the head. He tossed it back up to her and she spent the rest of the number screaming "I'm so sorry!"

Interview: 

_________________________________________________________

And of course,

_________________________________________________________

- The time Mike Faist tap-danced through a chair. Also during 'King of New York', he leapt onto a chair and his foot went straight through the seat. The other newsies rushed in front of him to try to cover up him tap-dancing with a chair around his leg.

Interview: 

(He also has a piece of the wood from the chair, but I can't find that video)