Senior administration officials, including Homeland Security Director Tom Ridge and Attorney General John Ashcroft, met Monday at the White House to discuss the latest information on terrorist threats. They agreed the nation is on "yellow," or "elevated," status.

A snow fence security perimeter encloses portions of the Mall around th Washington Monument in preparation for the nation's July 4 celebration.

According to the five-step color-coded threat assessment used by the White House Office of Homeland Security, yellow is the mid-point color, meaning the government considers the nation to be at a "significant risk of terrorist attacks."

"Orange," or "high," is the next level -- meaning the government considers there to be a "high risk of terrorist attack." "Red," or "severe," is the highest alert status, and means just what its name implies.