translation.en: We'd spent a lot of time designing this bridge, and we'd analyzed it, we'd checked it to codes -- to heavier loads than the codes -- and here it was doing something that we didn't know about.
translation.zh: 在设计桥上我们花了很多时间，也分析过它。 我们检验过负重了——我们用超过最高载重的重量检验过了—— 然后发生了一些我们当时根本不知道的事。