BTW, according to this
BBC article from yesterday, Douma is controlled by a group calling themselves
Jaysh al-Islam. Said group has been accused of
using chemical weapons in 2016 in Aleppo.
And as Schroeder pointed out in the US politics thread, it doesn't make much sense for Russia/Assad to do it at this point.
Now, I'm not saying it was them, nor am I saying that it wasn't Russia/Assad, but perhaps it would be wise to investigate it a bit before hitting the 'launch' button.