NEW YORK (AP) — Work to transform the largest undeveloped property in Manhattan from a railroad storage yard into a sleek new neighborhood of spiky high-rises and graceful parks got a formal start Tuesday, with developers and officials heralding it as the next big thing in a city known for them.

The $15 billion project, called Hudson Yards, calls for angular office skyscrapers and curvy apartment towers, a slate of shows and restaurants, an arts building and a public square in a 26-acre stretch of the island’s far West Side off Midtown — eventually. Tuesday marked the ceremonial groundbreaking for the first office tower, a 48-story building scheduled to be finished by 2015.