When the bombs fell on October 23, all of the staff except her left the museum. Having only been in Massachusetts for merely a month, Megan had nowhere to go and felt abandoned by her colleagues. Instead, she took a gun from the curator's desk and locked herself inside one of the rooms in the museum. Before doing so, she left an entry on the museum's operations terminal, hoping that someone would read it and come for her.
Megan Hayes is mentioned only in Fallout 4.