I looked a little more and an explosion for underground work could possibly make the Richter scale read up to 3.7 in magnitude. So 2.1 being a smaller blast for an exit door to a tunnel that escapes Washington’s underground system could be plausible. The area is a quiet little place 45 min north of Washington Called highland that is mostly residential which if I’m going to be running from the area from anything (that I do not know) but north on the map seems smartest unless they take water but I wouldn’t. So when/if anything that’s my assumption and if the exit is done then imo that’s the finishing touches.