Robert Stolarik for The New York Times
The final beam was lofted into place Monday atop the Renzo Piano-designed building in the meatpacking district that will serve as the new home of the Whitney Museum. The museum is leaving the Upper East Side for the downtown location in 2015. The top of the structure included an American flag, which was flown at half-staff to honor the victims of the Newtown, Conn., school shooting.