I just came across this interesting fact about New York City Marathon in the NY times.
In 1977, Wesley Paul, a child from Columbia became the youngest person ever to complete the New York City Marathon with an incredible time of 3:00:37. In the early years of the race several children competed.
Paul still ran a 2:38 personal best at 15, in the Houston Marathon. By the age of 16 he had 40 marathon under his belt.
At 16 he fractured his knee when a car backed into him while he was running. He never recovered!