The lights were back on at the New York Palace Hotel at 50th Street and Madison Avenue early Monday, but it was too late for some of those guests.
The outage was caused by a water main break that occurred just before 1 a.m. A Con Ed line was clipped, knocking out power to the 50-story building.
Backup generators on the eighth floor kicked in, but then the main break flooded the basement, where the fuel for the generators was kept.
Approximately 1,000 guests were staying in the hotel at the time, and hundreds were forced to evacuate. Some found lodging at other hotels, while others headed to the airport early.
Firefighters said they were concerned people may have been stuck in the elevators, but that apparently did not happen.
The situation was brought under control around 3:15 a.m., and power was restored.
No train service was affected.