Condoleezza Rice, who was President George W. Bush’s national security adviser at the time of the attacks, recalled the events of that morning.

“The attack came quite literally out of the blue,” she said. “An assault on our cities that we had not experienced since the war of 1812.”

Rice was at her desk at the White House when her executive assistant told her a plane had hit the World Trade Center. She thought it was an accident, as did Bush when she called him. But within 17 minutes, a second plane hit the other tower. The president was rushed to Air Force One, and Rice was hurried to a bunker in the White House.

At the Pentagon, Defense Secretary Donald Rumsfeld couldn’t be reached. His phone simply kept ringing. It turned out that Rumsfeld was trying to pull people to safety, while his security detail begged him to get to safety.

“There was no doubt, the United States of America was at war,” Rice said.

“Here at the Pentagon, we feel the presence of 184 souls who were lost,” she said. “Behind every name that we recite, there is a story. A life that mattered. A future unfulfilled. A void, a vast empty space. In the heart of a husband, a wife, a son, a daughter, a sibling, a colleague or a friend.”

Rice remembered the many Americans she saw who stepped up, went without sleep, and made immense sacrifices to serve their fellow Americans.

“Those of us in authority on that day did not see the nature of the danger in time to prevent the attack of 9/11,” she said. “We did what we knew to do. But by definition, it was not enough.”

Rice said they owe a “deep debt of gratitude” to the armed forces and intelligence services who prevented future attacks. But as national security adviser at the time, she also shared a deep sense of personal remorse that they did not prevent the attacks.

“I will always carry deep personal remorse for the pain that you, the families of the fallen still feel, and for the trauma that our country endured,” she said.