Does the film have an unhappy ending?

Of all the films I have seen, Titanic is the one I like best. Titanic is a tragic love story film. It is about the sinking of a luxury liner on its first voyage across the Atlantic Ocean. The film is made in America. It is based on the true story of the Titanic disaster that occured in 1912. The main characters are Jack Dawson and Rose DeWitt Bukater. Jack Dawson is a young and generous adventurer. While on board, he saves Rose DeWitt Bukater from killing herself, and although she is already engaged, the two fall in love. The ship hits an iceberg and sinks rapidly. More than a thousand people die in the disaster, including Jack Dawson. Critics say it is a must-see because the story is moving and the acting is excellent
1.  Does the film have an unhappy ending?
2. What have critics said about it?