California has the strictest building codes and fire regulations in the nation, requiring all emergency exit doors to be unlocked to ensure free egress should an emergency occur. The museum invited local fire marshals to take part in the decisionmaking for a new security system upgrade. Prior to installing the system, the museum had relied on guards; closed-circuit television monitors; motion, heat, and smoke detectors; and a computer-operated central access alarm and control room. The new system uses electromagnetic locks that provide 1,200 pounds of holding force yet release immediately in the event of an actual fire or smoke alarm. As a crime deterrent, these locks also include a delayed exit feature that keeps the door locked for 30 seconds and sounds an alarm if an unauthorized person hits a door's panic bar. Power to the door shuts off in a real emergency. Security personnel staffing the central alarm station can see at a glance if the exit doors are secure. Finally, unlike electrical locks, these locks have no mechanical devices to block the door in any way.