Agency Is Under Scrutiny for Overlooked Messages
The National Security Agency intercepted two cryptic communications on the day before the Sept. 11 attacks that referred to a major event scheduled for the next day, but analysts at the secret eavesdropping agency did not read the messages until Sept. 12, American intelligence officials said today.
One of the conversations intercepted by the agency on Sept. 10 said "the big match" was scheduled for tomorrow, referring to Sept. 11. A second message called the next day "zero hour."
Agency analysts did not process, translate and review the intercepted Arabic communications until the day after the attacks, and so President Bush and other senior policy makers were not told of the possible warning until it was too late.
http://www.nytimes.com/2002/06/20/national/20INQU.html