In addition to the birds reported by Gary Allport today, I saw the 
following warblers and vireos at a slightly later time (0900-1000) in 
the Maintenace Yard:

1 Blue-headed Vireo
1 White-eyed vireo
2 Black-and-white Warblers
3 Nashville Warblers

and the ubiquitous Yellow-rumped Warbler


Wallace
Washington, DC