Abstract: A two-stage pyrotechnic gas generator for inflating an airbag has a housing with first and second chambers each having gas release apertures. The chambers are separated by a partition having an opening. Running through the gas generator is an essentially contiguous train of combustible material including a train of fast burning material passing through the first chamber to the opening, a pyrotechnic delay element associated with the opening, and a train of fast burning material within the second chamber. The first and second chambers each include a quantity of propellant deployed to be ignited by the corresponding train of fast burning material. An initiator, associated with the first chamber, is configured to initiate combustion of the essentially contiguous train of combustible material. As a result, the second quantity of propellant is ignited at a predefined delay relative to ignition of the first quantity of propellant to achieve precisely timed two-phase inflation with a single electronic initiator.