WASHINGTON — Part of a retaining wall at the 3rd Street Tunnel project collapsed Tuesday morning, causing delays northbound. The ramp to Massachusetts Avenue is closed. D.C. Department of Transportation spokesman Terry Owens tells WTOP that part of a retaining wall has collapsed. He says as far as he knows, no one was hurt and no cars were damaged. The collapse occurred in the area of the long-term 3rd Street Tunnel project.  

3rd ST Tunnel NB ramp to Massachusetts Ave: BLOCKED + RIGHT lane NB tunne BLOCKED, construction closure #DCtraffic pic.twitter.com/7OibVyjjov

— WTOP Traffic (@WTOPtraffic) September 22, 2015