A cable tray and at least one side wall bracket secured to the cable tray wherein the cable tray has a plurality of transverse and longitudinal wires. The side wall bracket has angled legs defined by a U-shaped inside leg portion and a hook that leads to an outside leg portion. The inside leg portion of each angled leg engages a first surface of side longitudinal wires and bottom longitudinal wires and the outside leg portion of each angled leg engages a second surface opposite the first surface of side longitudinal wires and bottom longitudinal wires to secure the side wall bracket to the cable tray.