Titanic, oceanic, and brittanic were the three white star ships in that line. The lucitania was a different ship altogether.Allegedly white star lines made 2 or 3 identical ships, Titanic being one and don't quote me, Lusitania being the other one. And the Titanic was purposely sunk through welding of the hull in route... It never hit an iceberg..
Not sure how the titanic (Oceanic rebadged) was sunk, but I'm confident it was the goal of that trip.