On September 11, a Marilyn Monroe impersonator sang a sultry rendition of "Happy Birthday" to an executive at the Virginia headquarters of the Society for Human Resource Management. The brief performance, which took place in a conference room with about 75 employees, came after remarks honoring the 24th anniversary of the 2001 terror attacks. Two former staffers who were present at the gathering, recordings of which were reviewed by Business Insider, said it was uncomfortable to see - and not just because it was sexually suggestive.