WASHINGTON (AP) — Twice this year alone, Air Force officers entrusted with the launch keys to nuclear-tipped missiles have been caught 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 have told The Associated Press.

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 damage an intruder could cause, including the compromising of secret launch codes.