There's a reason for the children's song "London Bridge is Falling Down." Over the years, there were continued warnings from children who claim that the bridge was falling down, and in fact, in 1962 it nearly collapsed. It was around that time that American Robert McCulloch bought the bridge and re-assembled it in Lake Havasu, Arizona. The current bridge over the River Thames, which hundreds of tourists and vehicles cross each day, opened to traffic in 1973 replacing a 19th-century stone-arched bridge, which also superseded a 600-year-old medieval structure.