LL Cool J won't perform in the Wawa Welcome America Fourth of July Concert on Benjamin Franklin Parkway on Friday, saying he won't "cross a picket line" amid the ongoing strike in Philadelphia involving the city's largest municipal workers' union.

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.

In this life we are only measured by how we uphold our morals and standards, by what we choose to fight for through participation or protest,” she wrote on her Instagram story.