A Capitol Fourth rehearsal underway

Rehearsals are underway for tomorrow's "A Capitol Fourth" concert outside the U.S. Capitol.

Dancing With the Stars’ host Tom Bergeron is heading up the event. Barry Manilow, Candice Glover, Megan Hilty and Scotty McCreery are all practicing for tomorrow’s performances.

Fences and security checkpoints are all in place on the National Mall. The July Fourth celebration will be the first huge public gathering in downtown D.C. since the Boston Bombings. Bags will be searched.