Air Force officers entrusted with the launch keys to long-range nuclear missiles have been caught twice this year leaving open a blast door that is intended to help prevent a terrorist or other intruder from entering their underground command post, Air Force officials said.

The blast doors are never to be left open if one of the crew members inside is asleep — as was the case in both these instances — out of concern for the trouble an intruder could cause, including the compromising of secret launch codes.