During the special event, Olsen, 26, looked classy and cute in long sleeved black mini dress with white ruffle on the front. She completed her look with a green broach, silver high heels and tousled shoulder-length blonde tresses.
As she posed for some pictures outside of the building, a sudden gust of wind blew her skirt up, flashing her light nude undergarment.
The 26-year-old actress was shocked and made hilarious expression as she tried to pull down her skirt with her right hand.