Credit: The gate for the Anacostia-Bolling joint military base in Washington, Wednesday, April 17, 2013, where mail for the White House is sorted. In a capital city on edge, letters sent to President Barack Obama and a Mississippi senator tested positive for poisonous ricin in preliminary checks, and authorities chased a stream of reports Wednesday of other suspicious-looking items sent to senators in Washington and beyond. (AP Photo/Alex Brandon)
Testing underway on suspicious letter that sickened 11 at area military base
