A fire suppression system for producing an inert gas mixture having a minimal amount of carbon monoxide, particulates, or smoke. The inert gas mixture may be generated by combusting a gas generant. The gas generant may be a composition that includes hexa(ammine)-cobalt(III)-nitrate. The fire suppression system also includes a heat management system to reduce a temperature of the inert gas mixture. In one embodiment, the system includes multiple gas generators and is configured to ignite the respective gas generant of each gas generator in a predetermined, time based sequential order. For example, the gas generant of each gas generator may be ignited in a sequential order at specified time intervals. Methods of extinguishing fires are also disclosed.