WASHINGTON — D.C. emergency responders and Metro workers will be out in force Sunday around the Navy Yard station. But rest assured: It’s only a drill.

The quarterly exercise — which is scheduled to run from 8:30 a.m. to 2 p.m. Sunday in the tunnel between the Navy Yard and Anacostia stations — will involve evacuation of a disabled train.

According to Metro, the full-scale response drill will “simulate real-world conditions to test coordination and communication between on-scene responders, Metrorail operations staff, Metro Transit Police and support personnel.”

More than 100 are expected to be involved.

The Navy Yard station will be open during the drill. But riders will need to use the New Jersey Avenue entrance, because the Half Street entrance will be closed.

In addition, Green Line trains will use a single track between Navy Yard and Anacostia from 7 a.m. to 2 p.m. on Sunday.

More information is available on the Metro site.