Thousands of people showed up to dance, slide down an ice hill, watch fireworks and celebrate America’s independence at the Rockin’ 4th of July at Big League Dreams on Thursday.Nice weather -- Thursday’s high temperature was 87 degrees, according to the National Weather Service -- brought out the crowds. Mansfield police estimate that 9,000-10,000 people attended, the largest crowd ever for the annual free event. The All Funk Radio Show kept the crowd boogying with funky tunes, while they visited, chowed down on hamburgers and hot dogs, took a swing at the smash car or played in one of the bounce houses. Special treats were the two icy sledding hills that gave youngsters a chance to chill out.The event wrapped with a 25-minute fireworks show, concluding with a huge pyrotechnic blast that startled and thrilled visitors. Despite many who were alarmed, the show went off exactly as planned.