Why did Superman destroy the Fortress of Solitude in the 2nd movie?

Answer 1

In "Superman II," Superman destroys the Fortress of Solitude to rid himself of the powers he gained from the yellow sun after he chooses to become human and live with Lois Lane. When he realizes that his decision has made him vulnerable and that the threat from General Zod and his allies is imminent, he decides to regain his powers by exposing himself to the sun again. The destruction symbolizes his struggle between his human desires and his responsibilities as a hero. Ultimately, he sacrifices his personal happiness to protect the world.