This post has been updated

When the Metropolitan Police Department tweeted three hours ago that it had found a “suspicious package” at the 1200 block of Fourth Street SE, it didn’t seem like much was up—how many suspicious package warnings do we get a week, anyhow?

But this package was different—it was an unexploded 1,000-pound military ordnance found on land that was once part of the Navy Yard and will eventually become a new Harris Teeter and residential building in a development known as The Yards. A reader sent us a picture of the unexpected surprise that construction workers happened upon this morning at the site, which was once a shipyard and ordnance plant for the U.S. Navy.

In related news, it was just this week that the U.S. Army announced that it was getting closer to finding an old weapons dump in the Northwest neighborhood of Spring Valley.

We’ll have more information as we get it.

UPDATE, 3:30 p.m.: WJLA reports that this isn’t the first time that ordnance has been found at the site, which used to be part of the Naval Gun Factory. For more on that, watch this following video: