DCPD is reporting that Mass Ave is closed at 1st and 2nd Sts. NE in both directions due to a fire investigation at Union Station. The fire stems from a third rail problem, and though WMATA reports trains are simply bypassing Union Station, it sounds as though the whole Red Line may not be moving at all.
UPDATE FROM WMATA, 9:43AM: Single tracking btwn Rhode Island Av & Judiciary Sq. Significant delays in both directions. Consider alternatives.