Dream: mass suicide in Washington

I woke up at 4am from a disturbing dream.

I was in Washington asking around, wondering what it was that the "authorities " were expecting. Why were so many troops there? Why the extra precautions?

What was the threat from outside?

It turns out it was a threat from inside.

First one, then another then another.

People were discovered in their offices in the Capitol and other government buildings.
Their minds had melted.
It wasnt a suicide pact, per se.
But low frequency sound weapons had made them susceptible to the idea of taking their lives.
Their anxiety was increased to the point that they couldn't inhabit their bodies any longer.
The interesting thing is that in my dream they invested a liquid poison.
No shootings or hangings or pills.
It was neat and orderly to clean up.

I saw someone come out of their office just as they had drunk the poison. They suddenly thought they had made a mistake! But it was too late. They died in the doorway.