Kara Zor-El was the last survivor of Argo City of the planet Krypton which had survived the explosion of the planet and had drifted through space. When the soil of the colony was turned into Kryptonite, lead sheeting was placed on the ground. Some while after the demise of Krypton, her parents Zor-El and Allura In-Ze got married and conceived her. She led a relatively happy childhood until she was fifteen when a meteor shower pierced the sheeting and the Kryptonians began to die of radiation poisoning.