7:20 p.m. Update: The situation in the tunnel has been resolved, officials say.
6:30 p.m. Update: Only the right lane gets by in the soutbound lanes. Delays extend to New York Avenue, according to emergency officials.
5:45 p.m. Update: D.C. emergency officials say there have been two accidents in the tunnel, with multiple vehicles involved. Crews are evaluating five or six people for injuries, but authorities say none of the injuries appear serious. D.C. police are on the scene.
Original post: D.C. emergency officials have responded to an accident scene in the southbound lanes of the Third Street Tunnel. Officials are investigating whether two separate incidents have occurred, and are evaluating several people for possible injuries.
Drivers should expect serious traffic delays.