The building was designed to be able to run for four days without exterior power through four 7,500-kilowatt (10,100 hp) emergency electrical generators, its own steam turbines, and tanks that could store 109,000 U.S. gallons (410,000 l; 91,000 imp gal) of emergency water. When it opened, the building contained 23 high-speed elevators capable of traveling 14,000 feet per minute (4,300 m/min).[1] As of 2020[update], the building has 30 elevators.[2] Floors 3 through 11 served as Bear Stearns' trading floors.