At one point in the film Titanic, the character Thomas Andrews (who was the naval architect who designed the ship) is talking with J. Bruce Ismay, the chairman of the steamship line that owned the Titanic. Ismay is incredulous about Andrews' pronouncement that the ship will sink in less than two hours.
ISMAY: But this ship can't sink.
ANDREWS: She's made of iron, sir. She can . . . and she will. It is a mathematical certainty.