A report distributed by the press corps accompanying Bush on his European tour said the president may attend the D-Day ceremonies in France and the G-8 conference in Sea Island, Georgia, next week as scheduled.
The report said the White House was waiting for the Reagan family to announce details of the various memorials.
As he heard the news, Bush immediately ordered flags to fly at half-staff on all federal buildings for 30 days beginning Saturday.
McClellan said Fred Ryan, Reagan's former Chief of Staff called Bush's Chief of Staff Andrew H. Card, Jr. and gave him the news. Card immediately went to Bush, who was in his room where he had retired for the night.
"He had just gone to sleep; Secretary Card woke him up," said McClellan.
Asked if the staff was caught by surprise, McClellan sai: "No one's fully expecting it until the moment arrives; we're all saddened by this news." Staffers scrambled to coordinate the statement and according to McClellan "a number of staffers have shared their memories of Ronald Reagan."
The president spoke from a hallway at the residence of the American ambassador's home, dressed in blue suit, blue shirt and maroon tie.
When asked if the Bush administration feels like they are following in the Reagan footsteps, McClellan said, "President Reagan was someone the President greatly admired for his leadership and vision and ability to set clear priorities. He lifted the entire nation up."
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