—Well, there’s a big sale at the Talbot’s on M Street, and I just wanted to get everyone else outta the way . . .
Ah, the warning wasn’t from an official source, my source says. Apparently, a local DC news agency holding a retreat in the area asked its employees to stay at a hotel out of the city and asked anyone not attending to stay at least 25 miles out of the city on Friday and Saturday. shrug
Finally got a response from Snopes. The supposed warning is probably a variant of this, the veracity of which has yet to be determined.