President Obama called President Calderon of Mexico from Air Force One to tell him that he was shocked and saddened to learn of the tragic death of Mexican Interior Secretary Francisco Blake Mora and seven of his Mexican government colleagues in a helicopter crash. The President said that his thoughts and prayers are with the families of those who were lost, with President Calderon, and with the Mexican people. The United States deeply regrets the loss of these officials who were close partners of the United States, and strong public servants for the Mexican people. President Obama reaffirmed the close partnership between the United States and Mexico, and pledged to stay in close contact and provide any assistance needed going forward.
Barack Obama, Readout of President Obama's Call to President Calderon Online by Gerhard Peters and John T. Woolley, The American Presidency Project https://www.presidency.ucsb.edu/node/302827