They are hearing from scanner information that it may be an ex-employee.
wusa9
1. RT @FixWMATA: Evacuating Discovery http://twitpic.com/2kahc5 1 minute ago via web
2. The gunman’s demands can be found here: http://savetheplanetprotest.com/ 2 minutes ago via web
3. Live streaming coverage of the Discovery Channel situation: http://bit.ly/9AlLwc 3 minutes ago via web
4. Appears he had some sort of explosive device, according to Cpl. Dan Friz with MoCo Police. Has taken at least one hostage. 13 minutes ago via web
5. @DaAnGrYASiAN can you call us at 202-895-5588? 26 minutes ago via web in reply to DaAnGrYASiAN
6. We’re hearing about a possible hostage situation at the Discovery Channel. If you have info or know someone there, please @reply us 29 minutes ago via web