Who killed Flashes mom?

Flashes' mom, Nora Allen, was killed by the Reverse-Flash, also known as Eobard Thawne. In the storyline, Thawne travels back in time to kill her, which becomes a pivotal moment in Barry Allen's life and contributes to his transformation into the Flash. This act of violence is a key element in the ongoing conflict between the Flash and the Reverse-Flash throughout the series.