Unbreakable

The Unbreakable was an Imperial-class Star Destroyer that served as the flagship of Admiral Corleque of the Galactic Empire. When the Scourge infected the droids of the Executor, the flagship of the Sith Lord Darth Vader, Corleque was dispatched aboard his Star Destroyer with a fleet of four others to destroy it along with everyone on board, including Vader and Admiral Firmus Piett. However, Corleque hesitated momentarily due to Piett having previously delayed an evacuation transport for four seconds to save him. Corleque's delay gave Vader and his own droids enough time to re-enable the fail-safe device that disabled all droids aboard the Executor. However, Corleque's own flagship became infected by the Scourge, and its fail-safe was destroyed. As he did before, Piett waited for four seconds, but Corleque was unable to control the Scourge. Piett ordered the other vessels to fire on Corleque's flagship, destroying it. Corleque, however, survived, but was punished with demotion for allowing his Star Destroyer to fall to the Scourge.

Text and facts from the “Unbreakable” article on Wookieepedia, licensed under CC BY-SA 3.0. Modified for this site.