Why didn't fdr celebrate d-day along with the rest of the American people?

He was more grateful & relieved than joyous. He understood the great challenges ahead & the cost in lives. The invasion & struggle at Normandy was very bloody and did not end the war. It opened up another land-front against Germany. In the next 11 months of ground fighting, American casualties would mount. Celebration would be the wrong reaction to the start of the invasion for the US President. Instead he asked for Americans to pray for the success & safety of American soldiers, sailors & airmen involved in the invasion.