Courtesy of Alan Henney and the SCAN-L newsgroup:
Arlington County and the Pentagon will conduct an emergency response test for a simulated biological attack. This will include a number of Arlington emergency vehicles and public safety personnel and will help us to respond better in an actual emergency. These efforts are part of our ongoing partnership with the Pentagon to improve safety, security and emergency management.
The only road closure will be eastbound South Gate Road from Orme Street to Columbia Pike; eastbound traffic will be diverted onto Orme Street from 6am to noon. All other roads will remain open. Curiosity about the test may cause some traffic congestion in the immediate area.
The test is completely safe for participants and bystanders. In the event of unfavorable weather conditions, alternate test dates are June 3, 16, and 17.