1. Cordless Circular Saw
2. Heavy Duty Rubber Gloves
3. Rubberized Boots
step one, find point of entry for power to building
step two, throw primary breaker disabling emergency lighting and all other sources of power
step three, saw open conduit which carries high voltage from breaker box, after the point of disconnect
step four, place "hot" and "nuetral" leads which were just sawed onto floor.
step five, get to the restroom and use the saw to cut open flexible cold water pipe under the sink.
step six, repeat for all restrooms
step seven, prop bathroom doors open using trashcans or cleaning supplies found in bathrooom
step eight, return to point of entry for electrical power and throw primary breaker back on.
step nine, find someplace to hide out whilst not touching anything conductive and wait for the place to flood and everyone to get electrocuted.