As the storm battered New York City on Monday, the hospital's basement, lower floors and elevator shafts filled with 10 to 12 feet of water, causing a power outage, CNN reports.
This sudden flooding sent the emergency generators into action, but just two hours later, 90% of the power went out – forcing hospital staff to evacuate patients.
"Things went downhill very, very rapidly and very unexpectedly," Dr. Andrew Brotman, senior vice president and vice dean for clinical affairs and strategy told CNN. "The flooding was just unprecedented."
Patients included four newborn babies who relied on respirators to breathe. With no power to run the respirators, each baby was carried down nine flights of stairs while a nurse manually squeezed a bag to deliver air to the baby's lungs.
"This is a labor-intensive, extremely difficult process," Brotman added.
With 1,000 staff members (which included doctors, nurses, residents and medical students) joined by firefighters and police offers, the evacuation was completed by 11 a.m. Tuesday morning.
While NYU Langone Medical Center usually treats about 800 patients, it discharged hundreds over the weekend in anticipation of the impending storm.