Although the 18th century BC copy of the Atrahasis (Atra-Hasis) epic post-dates the early Gilgamesh epic, we do not know whether the Old-Akkadian Gilgamesh tablets included the flood story, because of the fragmentary nature of surviving tablets. Some scholars argue that they did not. Tigay, for example, maintains that three major additions to the Gilgamesh epic, namely the prologue, the flood story (tablet XI), and tablet XII, were added by an editor or editors, possibly by Sin-leqi-unninni, to whom the entire epic was later attributed. According to this view, the flood story in tablet XI was based on a late version of the Atrahasis story.