This is from CNN:
Several people were injured Monday after a person fired shots inside the Washington Navy Yard, the U.S. Navy said.
The injured included a Washington, D.C., police officer who has been hospitalized, said Metropolitan Police Department spokeswoman Saray Leon.
The incident occurred at 8:20 a.m. when several shots were fired inside the headquarters for Naval Sea Systems Command in southeast Washington, D.C. An "active shooter" remained inside the building, said the Navy and Leon, the police spokeswoman.
Emergency personnel, the FBI, U.S. Capitol Police and local D.C. police responded to the shooting, shutting down traffic in the area on the district's south side along the Anacostia River. Some people are being evacuated and others are sheltering in place.