Abstract: A shutter assembly has a plurality of laths which extend between a pair of vertically extending side channels disposed to either side of a doorway, window or the like. A number of the laths are strengthened and are hollow box sections through which a pair of wire cables extend. The wire cables are anchored to retention members which can move vertically in the side channels. The remaining laths have windlocks at their ends which are located in and are moveable in the side channels. The wire strengthened laths are alternately interlaced with the remaining laths. The wire cables give additional strength to the strengthened laths and are sufficiently strong to withstand a heavy blow to the shutter assembly in the vicinity of the strengthened laths, extending with the blow and thereby absorbing energy rather than breaking.