Abstract: An apparatus is provided for automatically unlocking the guard bars on a window in response to the output signal of a fire detection device. In a preferred embodiment a smoke alarm having a pair of relay-controlled contacts is used in conjunction with a solenoid arrangement to unlock the window bars. Power to the smoke detector and the solenoid circuit is supplied by a rechargeable battery, so that in the event of power failure the automatic window bar unlocking apparatus continues to operate.