Board Thread:Questions and Answers/@comment-26242189-20160422234238/@comment-27701762-20160423014920

To my recollection, there is no indication that Asgore was actually responsible for their deaths. It is possible that he killed them, but it is also possible that they were killed by other monsters, or that they died in various traps in the Underground. Though my memory has been fading on these lines, so I may just be forgetting something.