TRENTON, N.J. (AP) - Two gunmen opened fire at an all-night arts and music festival early Sunday morning, sending people running over each other in the scramble to safety, authorities said. One suspect was killed and 22 people were injured.Of 17 people treated for gunshot wounds, four of them, including a 13-year-old boy, remain in critical condition late Sunday morning, said Mercer County Prosecutor Angelo Onofri.