Cika wannan jumla:
Girgizar kasa ta 1994 ta Northridge ta bayyana wata matsala ta yau da kullun a cikin ginin ƙarfe-frame <unk> mara kyau da aka haɗa haɗin haɗin gwiwa <unk> kuma an sake duba ƙa'idodin gini don ƙarfafa su.