建筑倒塌的部分原因可以归结于除了楼板加固之外，在内部没有钢柱支撑起建筑。

Part of the reason that the buildings collapsed as they did is because aside from the floor reinforcements, there were no columns holding the building up from the inside.

youdao

双方的战斗人员都在隧道间不停地穿梭，隐蔽于巨大的工业设备和倒塌的公寓建筑的废墟楼板中。

The two sides of the combatants are kept in the tunnel between the shuttle, hidden in the huge industrial equipment and the collapse of the ruins of an apartment building in the floor.

youdao

计算结果说明，世界贸易中心倒塌的直接原因是火灾导致的钢材软化和楼板塌落冲击荷载引起的连锁反应。

The numerical results also show that the softening of steel under fire and impact load of top floors are the two main reasons for the collapse.

youdao