A sprinkler system is the main line of defense against fire. If properly maintained, it will contain and extinguish a fire.
External piping takes water from the street into the building's fire protection system. In the same vicinity are located the fire department connections which the fire engine will pump into in order to boost the pressure in the system.
Inside the building, the piping branches off to provide water throughout the building. Sprinkler heads are spaced uniformly throughout the building to provide complete coverage.
In the event of a fire, the sprinkler head will be activated by heat.
State law requires that all new high rise buildings built after July 1, 1974 must be sprinklered. The City of San Diego passed an ordinance in 1988 which requires that all non-sprinklered office high rise buildings be retrofitted with sprinkler systems.