User blog comment:Commdor/Game Informer ME3 Preview (Feb. 2012)/@comment-3053284-20120110110727/@comment-743796-20120110120301

Well... it's not that surprising when you think about it. Keep in mind that we find out in ME2 that Klendagon's Great Rift Valley was caused by a weapon powerful enough to disable a Reaper flying overhead 37 million years before the series proper.