Robert Downey, Jr. thrilled a group of superstorm Sandy volunteers on Monday (29Apr13) by making a surprise appearance at an Iron Man 3 screening held for teenage aid workers in New York City.

The actor made an unannounced visit to the Regal E-Walk theatre in Manhattan to honour youngsters from the Police Athletic League who have given their time to help rebuild areas devastated by the storm last October (12).

The teens cheered with delight when Downey, Jr. entered the building, and he personally thanked them for their hard work.

He told the crowd, "I just want to say thank you to the... Police Athletic League and all of you folks. I know you're all here because you've been doing something special in the five boroughs, for this great city.

"You're the future of the nation. I guarantee if you keep doing the right thing, you're going to be running the joint in a minute."

Downey, Jr. posed for photos with his star-struck fans, and told a reporter for the New York Daily News, "Of course (the visit means a lot as)... it's my hometown. Everywhere we drive, I have a memory of playing Frisbee in front of that office building or trying to sneak into the back door of a Rocky Horror Picture Show midnight showing, because I knew someone who was working concessions... Coming back here reminds me of my origins."