Given the task definition and input, reply with output. You are given a passage. You need to construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) its answer is the whole paragraph. Avoid creating questions that can be answered correctly without actually understanding the paragraph.

At 02:20 am on April 15th, 1912, the "unsinkable" Titanic slipped into the sea and began its descent to the ocean floor.
when did the Titanic sink?