In the first scene, it shows the titanic running into an iceberg. Thousands of people were still on it, and the crew was trying their hardest to re-course the ship but, it was suddenly too late.
In the second scene, it shows sinking into the freezing cold water. Unfortunately, the titanic ran out of life boats and they were taking women and children first, but for many people they had already drowned.
In the final scene, it shoes the titanic at the very bottom of the ocean split in half. Now to this day you can still dive down and still see the titanic at the bottom of the ocean.