Emergency workers treat the injured in ambulances on Friday night, July 4, 2014 after three boats collided near a Miami marina around the end of a fireworks display. Four were killed and a dozen others injured. (AP Photo/Miami Fire Rescue, Lt. Ignatius Carroll Jr.)

4 confirmed dead in Fla. boat collision

Three boats collided near a Miami marina around the end of a fireworks display, killing four and injuring a dozen others in a chaotic scene …