Above Manhattan's bustle, a reshaped public space

In the mid-20th century, it was a railroad; now it’s a public park. Built in the 1930s, 30 feet above the streets of Manhattan, the High Line was crucial for transporting cargo. But with the decline of rail transportation, it closed in 1980 and was abandoned. Almost three decades later, it opened again -- this time, as a shared space for greenery, art and leisure. Jeffrey Brown reports.