Simplify the following text for a Grade 7 native English-speaking person.
Original: After the Doolittle Raid on Tokyo , when the fact that the bombers had flown from an aircraft carrier remained highly classified , U.S. President Franklin D. Roosevelt told the press facetiously that they had taken off from Shangri-La .
Simplified: After the Doolittle Raid on Tokyo , the US President Franklin D. Roosevelt told the press that the airplanes had taken off from Shangri-La .