Most fire deaths are not caused by burns, but by the inhalation of smoke. In addition to heat and lack of oxygen, toxic gases in smoke are the most important lethal factor in uncontrolled fires. Drones are more and more considered the ultimate assistants in fire fighting operations. Drones or Unmanned Aerial Vehicles (UAV) provide a critical top-down perspective on hazardous areas. This is useful in dealing with most fires, and particularly important and effective in dealing with fires with high risk sites. There is an urgent need for small, low weight, low flow, real-time gas sensors with high specificity that can be integrated into UAV. The availability of such sensors can save lives as UAVs can detect and map toxic gas fields in open fires and evaluate how they spread. In addition to the integration in UAVs, such sensors can be integrated in firefighter's cloths or installed in the fire-sensitive places. In FireSpec, we propose the concept of an integrated wavelength modulation spectroscopic sensor for real-time hazardous gas detection based silicon photonics integrated chip including a series of InP lasers, a gas probe and InP and detector.