Kryptonite.
superman killed badguys but not the inocent
Doomsday killed him in the 1992 story-arc The Death of Superman
Superman does not fear any noble gas. In the "Death of Superman" comic storyline, Superman is killed by Doomsday, not a noble gas.
Yes he killed Superman.
North Mission Road - 2003 Who Killed Superman was released on: USA: 28 August 2006
Superman doesn't exactly have allergies, but the space rock "kryptonite" weakens his powers.
That is Superman you noob!!
cryptonite
Batman had the upper hand on Superman & could have killed him with the kryptonite spear, until Superman convinces Batman to 'save Martha'.
Kryponite can kill superman, Magic can too. But doomsday actually killed him but he came back. I hate superman though.
he is superman, or Clark Kent, and the rock is kriptonite...
Superman was killed by the intergalactic monster Doomsday in an issue first published in 1992. But he did come back to life after four other characters had been introduced- Superboy (imperfect Superman clone)/ Eradicator (Kryptonian anti-hero)/ Steel (John Henry Irons in iron suit)/ Cyborg Superman (evil villain).