Abstract: There is described a fire-fighting apparatus comprising a housing comprising an upstream air inlet and a downstream fire-extinguishing stream outlet and a hollow body therebetween, wherein the housing houses an air stream traveling at high velocity; and a spray assembly concentrically mounted to the housing. The spray assembly comprises a fluid inlet connected to a source of fluid outside the housing; and a plurality of injecting assemblies fluidly connected to the fluid inlet and designed for breaking down an inflow of the fluid into droplets and projecting the droplets of the fluid within the air stream in a multiphase fire-extinguishing stream. The injecting assemblies each comprises a fluid outlet; a base plate through which extends the fluid outlet; a holding structure mounted to the base plate and extending downstream therefrom, and a unibody jet-fragmenting device mounted to the holding structure facing the stream of fluid exiting the fluid outlet.