After a daylong standoff, authorities shot and killed an armed man wearing an explosive device who had taken three hostages at the Discovery Channel’s headquarters in Silver Spring, Maryland, just outside the District of Columbia. Most of the hundreds of employees, including children at an on-site daycare center, had already been evacuated, police said. The station was airing its normal broadcast. The three hostages were safe and out of the building, the police said. The 43-year-old suspect, James Lee, was killed by a police officer inside the building when he pointed a handgun at one of the hostages, said Montgomery County Police ...