REAT MILLS, Md. - Nov. 2, around 5:45 p.m., police responded to reports of a barricade situation on Foxchase Drive in Great Mills.

The St. Mary's County Sheriff's Office told TheBayNet.com that the situation is ongoing as of 7:46 p.m. and Maryland State Police are handling the scene.
http://www.thebaynet.com/articles/11...eat-mills.html

Not sure if it's still on-going but be careful in the area.