LL Cool J says he won't perform at Wawa Welcome America in Philadelphia until the city and the largest municipal workers' union come to an agreement amid an ongoing strike.

A sour note for Philly's Party on the Parkway. Both headliners of the Wawa Welcome America Fourth of July concert, LL Cool J and Jazmine Sullivan, have canceled their performances, refusing to cross the picket line as the strike by thousands of city workers stretches into its fourth day.