The ordeal began shortly before 5 p.m. when the power went out, leaving the two tram cars, which each can hold 125 people, motionless on cables that rise as high as 250 feet above the East River between the East Side of Manhattan and Roosevelt Island.
Officials said the diesel generator that powers the system failed, and then the backup generator stopped working as well. Efforts to manually crank in the cars back also proved fruitless, officials said.