<human>:  Why did the Titanic sink?
<bot>: The Titanic sank because of a collision with an iceberg. The collision caused the ship to break in half, and the ship sank within about 20 minutes. The collision was caused by the iceberg, which was not spotted by the lookout on the ship. The lookout was in charge of watching for icebergs, and he failed to spot the iceberg, which was a large part of the reason the ship sank.