Malfunction closes bridge on S. Capitol St. Sunday was not the best of days for either the Washington Nationals baseball team or a neighbor on South Capitol Street, the Frederick Douglass Memorial Bridge. The Nationals lost to the Mets in New York, while back at home, and near the team's stadium, the swing span of the bridge got stuck. The bridge, sometimes called the South Capitol Street bridge, carries South Capitol over the Anacostia River just south of the ballpark. On Sunday, the swing span underwent its monthly test - and could not go back to its original position, according to the District's Department of Transportation. When the bridge mechanism functions properly, a section of roadway lowers, then pivots 90 degrees, allowing the passage of vessels that would otherwise be too tall. A spokeswoman for DDOT said the test was expected to close the bridge to road traffic from 4 a.m. to 9 a.m. But as the result of an apparent electrical problem, the span remained in the open position four hours longer than scheduled. Traffic was diverted to the 11th Street Bridge in the meantime. Few of the 70,000 drivers estimated to use the bridge on weekdays are likely to have seen the swing section in operation. It is used at times by ships headed to and from the Washington Navy Yard, just upriver. It also was used on a visit here by a tall sailing ship. Constructed in 1950, the structure, which offers spectacular views of the Washington area, was repaired several years ago, but plans were reported last year to replace it with a new bridge in the same area.