A door unlocking system includes a receiver adapted to detect wireless signals having a signal ID emitted by at least one mobile device to be carried by an authorized person; a microcontroller interfacing with the receiver, the microcontroller programmed to store a valid signal ID and compare the signal ID of the wireless signals to the valid signal ID; a lock operating mechanism interfacing with the microcontroller; and a door lock interfacing with the lock operating mechanism, the microcontroller programmed to unlock the door lock via the lock operating mechanism when the signal ID of the wireless signals corresponds to the valid signal ID. A door unlocking method is also disclosed.