50 years ago, 1964: The Russians freed two U.S. airmen whose reconnaissance plane was shot down by a Soviet fighter over East Germany. Communist East Germany asserted they were released after the U.S. gave assurances that there would be no more occurrences of air space violations.
25 years ago, 1989: Cleanup efforts were stalled after aerial bombing failed to disperse the biggest oil spill in U.S. history, blackening icebergs and pristine waters teeming with marine life off southern Alaska. Nearly 36 hours after the spill, almost nothing was being done - worrying biologists, state officials and fishermen.
10 years ago, 2004: The panel investigating the Sept. 11 attacks did not uncover a single event that would have prevented them, but found numerous missteps by the Clinton and Bush administrations. Miscommunications, flawed policy making and bureaucratic breakdowns were among the the problems.