The death occurred around 5:00 am (1000 GMT), CNN reported. Authorities determined that there was no threat to the surrounding area in southeast Washington.

But otherwise, details were scant.

The dead marine's identity was not released.

A spokeswoman for the city's Metropolitan Police said an investigation was in its early stages but that for now, no criminal charges had been pressed.

The Marine Corps could not immediately be reached.

The barracks, sometimes known as "8th & I" for its location, is the oldest active post in the Marine Corps, founded in 1801 under President Thomas Jefferson, according to its website.

Marine units stationed there perform both ceremonial and security duties in the US capital. They include the famed Marine Drum and Bugle Corps, the Marine Band and the Marine Corps Color Guard.