A manual lung ventilation device and method suitable for acute manual respiratory resuscitation and lung ventilation of a person are disclosed. The manual lung ventilation device includes a nasal interface in fluid communication with a flexible chamber. The nasal interface being held in the proper position on the person by a headgear and at least one securing device adapted to connect the nasal interface to the headgear. The device may be formed as a single component to allow an operator to rapidly position the device on the person to be ventilated and operate the device with one hand.