In 1970, steel box-girder bridges in Milford Haven, Wales, and in Melbourne, Australia, failed spontaneously while under construction. Both were among the longest structures of their kind and were thought to be just natural applications of existing technology.
1970年，威尔士米尔福德港和澳大利亚墨尔本的箱形钢梁大桥在建筑过程中自然坍塌。这两座大桥拥有各自类型中最长的构架，被看成是现有技术的自然应用。