A man stabbed a woman and then was shot by a security guard at Washington’s Union Station on Friday, sending people fleeing outside as trains were briefly stopped and officers converged on the massive transit hub. Hours later, D. C. Police Department spokesman Officer Sean Hickman announced the man’s death. The man has not been identified. The woman’s condition was not known, and her identity was not released. The incident came on the 14th anniversary of the Sept. 11 terrorist attacks, but police said there was no apparent connection between the two.