The large damage to steel gymnasiums of elementary or junior high schooIs in the western Hiroshima Prefecture that incIuded Hatukaichi, Ohno and Ohtake caused by the 2001 Geiyo Earthquake was occured. The main damage to the gymnasiums was the fracture of the connection concrete at the top of column. The concrete strength at the top is estimated by use of the collaapse mechanism theory. It is confirmed that the connection concrete at some gymnasiums may be destoroyed by the base-plates of roof beams.