A 15-year-old girl  collapsed and died  near the finish line of the Leiden Marathon in the Netherlands on Sunday, sparking a conversation about the potential risks of long-distance running as the sport becomes more popular with teens and kids. The Dutch teen had been competing in the half marathon — a 21.1-kilometre run — when she collapsed about two hours after the start, according to race organizers . Paramedics were unable to resuscitate her. Police told local media it was a "health issue," and haven't given a cause of death, according to RTL, a Dutch news site. But the tragedy has nonetheless reignited a debate over age limits in long-distance running. The marathon's rules said participants in the half marathon needed to be at least 16 years old.…