A man known for protesting the Discovery Channel's environmental programming stormed the network's Maryland headquarters carrying a handgun on Wednesday, holding three people hostage for hours until he was shot and killed by police, according to a CNN report.

 

He entered the building in Silver Spring around 1 p.m. and appeared to have a bomb strapped to his chest, police said. After hours of negotiations, the Montgomery County Police Department announced just before 5 p.m. that they had set off smoke bombs, allowing sharp-shooters to take the gunman down. All hostages escaped safely.

 

The report said an explosive device may have detonated, and the suspect may have brought other devices into the building. The suspect was identified by Discovery Communications as James Jay Lee of San Diego, Calif., a man well-known to the building's employees because of his history of protesting the network. The report said the gunman had been wearing "what appeared to be metallic canister devices" when he entered the building.