Pre-9/11 Missteps By FBI Detailed / Washington Post, 10 Jun 2005

http://www.washingtonpost.com/wp-dyn/content/article/2005/06/09/AR2005060902000.html
Dan Eggen
"The inability to detect the Sept. 11, 2001, hijacking plot amounts to a 'significant failure' by the FBI and was caused in large part by 'widespread and longstanding deficiencies' in the way the agency handled terrorism and intelligence cases, according to a report"

Report - PDF - http://www.usdoj.gov/oig/special/0506/final.pdf