Several of President Barack Obama's top national security advisers stood on a silent, windy tarmac Wednesday night to watch as the bodies of six U.S. soldiers killed by a rogue Afghan policeman returned to U.S. soil.

The six were killed in Afghanistan on Monday when the border policeman turned his gun on his American trainers as the group headed to shooting practice. The gunman was killed in the shootout in Nangarhar province near the Pakistan border.