That was the work of the core's 47 steel columns braced with sheetrock.

那是用石膏板支撑的核心筒的 47 根钢柱的工作。

Steel columns lined the exterior perimeter, connecting to the core of the building via the floors.

钢柱排列在外周边， 通过地板连接到建筑物的核心。

But here's the problem: the impact had scraped the fire-resistant coating off the steel columns and beams, and the jet fuel had ignited a raging fire.

但问题来了：撞击刮掉了钢柱和钢梁上的防火涂层，喷气燃料点燃了熊熊大火。