Hi PJ2
The TITANIC was unsinkable, but for an un-designed for event (clogged Pitots?), the way she struck the iceberg.
She was built of a horizontally stacking series of watertight compartments. But she struck the berg tangentially, a glancing blow. So she acquired a long gash in her hull, the first seven compartments communicating with the sea. A head on would have smushed her to three/four compartments back, and she would have remained on the surface.
Tragically, she should have been steered into the iceberg, not away. She sank to the bottom of the Atlantic, 12,500 feet down. At 2am, her Captain was called back to the bridge, (familiar?). He was too late, and could not have helped.
Hubris, Sir, indeed. Boasting at Nature's door, not advised, eh?
Take care,