Abstract: A precast, prestressed concrete truss which spans between exterior columns and forms an interior or exterior load bearing wall of a building. The truss includes top and bottom chords interconnected by at least one web member. Prestressed reinforcing members in the top and bottom chords apply a compressive stress in the chords. The top and bottom chords are configured to support concrete planks that form a floor and/or a ceiling of a building in which the truss is used. When used as an interior load bearing wall, the truss can include at least one opening that forms, for example, a corridor passage large enough for a person to walk through the opening. When used as an exterior load bearing wall, the truss can include at least one window opening.