In Star Trek: Generations, which starship is destroyed during the film?

In Star Trek: Generations, the starship destroyed during the film is the USS Enterprise-D.

The Enterprise-D is destroyed when Captain Jean-Luc Picard orders its saucer section separated during a battle with the Klingon sisters Lursa and B'Etor. Their attacks severely damage the ship's warp core, causing an explosion that tears apart the engineering section. The saucer crash-lands on the surface of Veridian III, but its crew survives.

The destruction is an important transition in the film. The Enterprise-D had been the central starship of Star Trek: The Next Generation, and its loss makes room for Picard and his crew to move to the newer Enterprise-E in later stories. The film also shows the USS Enterprise-B, commanded by Captain John Harriman, during its earlier maiden voyage, which can cause confusion about which Enterprise is destroyed.

The saucer's crash is one of the franchise's most recognizable starship-disaster scenes. Unlike the Enterprise-D, the Enterprise-E remains the principal ship for the later Next Generation films.