Callos

Callos was a planet inherent with animal and plant life.

In 2 BBY the Galactic Empire attacked Callos under the command of Darth Vader. Black Squadron, Vaders personal unit was assigned a carpet bombing over inhabited area, after the battle ended. Juno asked, if this was really needed, so Vader changed the mission to bombing a single reactor unit. The destruction of this reactor mounted into a catastrophic chain reaction destroying the ecosystem of the entire planet.