By JOHN RABYCHARLESTON, W.Va. (AP) â¿¿ United Mine Workers of America President Cecil Roberts was among 16 people arrested Monday in the latest demonstration about bankrupt Patriot Coal's plan to eliminate health care benefits for 23,000 current and retired miners and their families. "I feel great," Roberts said as he was being placed in a Charleston police cruiser. More than 6,000 people from several states participated in a rally and subsequent march, which UMW spokesman Phil Smith called one of the largest organized by the union. An overflow crowd packed the Charleston Civic Center to hear speakers such as Roberts, U.S. Sen. Joe Manchin, Gov. Earl Ray Tomlin and AFL-CIO President Richard Trumka. The crowd then walked a few blocks to outside an office building containing Patriot's West Virginia offices for more speeches. The crowd held hundreds of signs and chanted phrases such as "promises kept, promises broke" and "shame on you." "I hope Patriot takes a good look at this crowd and these faces because you're going to get real familiar with us," Trumka said. "We're here to tell you a real simple message: Do what's right, or you won't have any peace. We'll be here until our brothers and sisters get the benefits that they earned." Patriot, which filed for bankruptcy in July 2012, claims its retiree health liability has ballooned to $1.6 billion. The company wants to modify its collective bargaining agreement and create a trust fund for retiree health care benefits, contending the move is needed to save 4,000 existing jobs. The union has sued Peabody Energy and Arch Coal in West Virginia, claiming they deliberately set up Patriot to fail so pension and health care benefits could be shed. After the 2007 spinoff, Patriot acquired mines that Arch had spun off into Magnum Coal. Smith, the UMW spokesman, said Patriot is seeking to eliminate health care benefits for 10,700 retired miners, plus 5,800 spouses and widows. The remainder of the proposed cuts â¿¿ about 6,500 â¿¿ involve active workers and their dependents.