|Screen capture from BBC website|
See this BBC page, with drawings of the ship tilting.
They had great problems lowering the lifeboats because on the low side, the boats would be crushed by the capsizing ship and on the high side, the lifeboats would not release.
We have all seen how the Titanic sank.... with a similar gash in the side, she gradually filled up and gracefully settled in upright position into the water, taking several hours to do it, and allowing lifeboats to be launched both sides (until it finally broke and pitched down nose first). The Costa Concordia, and the Herald of Free Enterprise in the 1980s are so high that they capsize sideways when punctured, the capsize happening in a few minutes. Also, the shallowness and nature of the seabed in the the more recent cases prevented the ships from sinking upright.
If buildings did this, there would be a very different attitude to structure. The twin WTC towers in New York were fatally damaged, but they fell vertically, like a collapsing accordion, within their own footprint. Imagine if the impact of the planes had caused the buildings to either snap (and the upper part fall) or to fall over onto its side like a collapsing tree, or like this ship has done.