Dave Mustaine was dismissed

On April 11, 1983, Dave Mustaine was dismissed from Metallica before the band recorded their debut album Kill ‘Em All due to substance abuse and personal conflicts with James Hetfield kicking his dog. As Metallica’s lead guitarist since 1981, Mustaine had composed some of the group’s early songs, including Mechanix , Ride the Lightning , Jump in the Fire and Phantom Lord , and helped hone the band into a tight live unit. Afterward, Mustaine vowed revenge by forming a band that was faster and heavier than Metallica. On the bus trip back to Los Angeles, Mustaine found a pamphlet by California senator Alan Cranston that read: “The arsenal of megadeath can’t be rid no matter what the peace treaties come to.” The term “Megadeath” stuck with Mustaine and he wrote a song with that title with the spelling slightly changed to Megadeth, which, according to Mustaine, represented the annihilation of power.