You want the building to look good from the street to the rooftop. Sprinklers contain all but 1 percent of high-rise fires, Baum said. With a hiss, the sprinklers nearest the fire trip, and the air conditioning automatically shuts off. An alarm bullets to the Austin Fire Department with the time, floor and zone in which the fire was detected. Klaxons sound to evacuate the burning floor, the floors above and below, as well as the lobby.
All elevators ground themselves immediately, ignoring any calls on the way down.
Within 60 seconds, the tower's stairwells flood with air to keep smoke out while residents evacuate. Exhaust fans kick in to suck the noxious gases from burning carpet and plastics through vertical shafts built into the core of the building and out vents on the roof. Residents still on those floors might feel their ears pop. From that room, supplied with fresh air and made to withstand flames for an hour, firefighters monitor where smoke has been detected, control exhaust fans and track water flow to the sprinkler system. If they see evidence that the fire has spread, firefighters raise an alarm, calling another station's worth of equipment and personnel to the scene.