Gunman kills 12 at Navy Shipyard in DC

 A crazed gunman kills 12 at the US Navy shipyard in DC. From NBC News:

A former naval petty officer who apparently had a grudge against the Navy sprayed an office building with bullets at the Washington Navy Yard on Monday, killing 12 people in a rampage that paralyzed part of the nation’s capital, authorities said. It was the deadliest mass shooting in the United States since the massacre at Sandy Hook Elementary School last year.

Authorities said that the gunman, a civilian contractor and former Navy reservist identified as Aaron Alexis, 34, was killed after exchanging fire with officers who stormed the headquarters of the Naval Sea Systems Command in a massive law enforcement response. He packed an assault rifle and two other guns during his lethal rampage.