Intrigued shoppers peered over the railing of the Mall of America's rotunda as Top 40 hits blasted to crowds of people dancing the day away. The first Unified Dance Marathon offered 12 hours of dance-filled fun to benefit Special Olympics Minnesota. Dancers boogied and clapped as multiple hosts introduced new events, including a lip-sync competition and Zumba. "Pretty Little Liars" actor Keegan Allen made an appearance, and Australian singer-songwriter and actor Cody Simpson performed.