DAVIS-MONTHAN AIR FORCE BASE, Ariz. -- President Barack Obama and First Lady Michelle Obama greet members of the Davis-Monthan Air Force Base community after landing in Tucson, Ariz., Jan. 12. The President and the First Lady arrived at the base before traveling to attend the memorial service commemorating the six lives lost Jan. 8 in Tucson, Ariz. (U.S. Air Force photo/ Senior Airman Brittany Dowdle)