WASHINGTON (AP)  President Bush has marked the fifth anniversary of the creation of the Department of Homeland Security and says it's hard to imagine that the country has reached this milestone without another attack against it. The president, in a speech at the department, says the danger to the country has not passed and that U.S. officials have been able to disrupt numerous planned attacks. He said one of them involved flying a plane into the tallest building on the West Coast and another called for blowing up passenger jets over the Atlantic. Bush says that in the face of this danger, the nation must never let down its guard. Copyright 2008 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed. Enlarge By Larry Downing, Reuters President Bush is introduced by Secretary of Homeland Security Michael Chertoff during the celebration of the fifth anniversary of the Department of Homeland Security at the DAR-Constitution Hall in Washington, D.C., Thursday. Conversation guidelines: USA TODAY welcomes your thoughts, stories and information related to this article. Please stay on topic and be respectful of others. Keep the conversation appropriate for interested readers across the map.