Having to inform the then-President of the United States that two planes had careered into both of the World Trade Center towers in front of a classroom full of children isn't the easiest job, but it's one that Andrew Card had to complete.
The 77-year-old was the White House Chief of Staff serving under George W. Bush when reports began to roll in that the hijacked aircrafts had smashed into the buildings in New York City.
As chaos was erupting in the Big Apple - which would result in the deaths of 2,996 people - the Commander in Chief was visiting the Emma E. Booker Elementary School in Sarasota, Florida, and reading a book with a classroom full of young children.
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Bad timing doesn't even begin to cover it - but Card knew he had to somehow communicate to Bush that there was something extremely sinister going on, without alarming the school kids and staff. Take a look at this:
In the room packed with pupils, teachers and photographers, the then-President's right hand man approached him in the middle of a reading exercise and whispered two haunting sentences into his ear.
Card admitted he was left wrestling with how to word the news that a second plane had hit the World Trade Center and that it was no accident - the US was under attack.
The historical moment, which has been immortalised in footage, saw the Chief of Staff lean over to the President to provide him with an update which nobody wanted to hear.
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In the BBC documentary 9/11: Inside the President's War Room, Bush recounted the moment he found out the news which changed the landscape of his nation forever.
Bush, who is now also 77-years-old, explained: "9/11 would become a day to remember. It's the job of a President to protect the American people from harm. Some President's don't need to worry about that and some do. And it turns out that I was one that did."
He then revealed the chilling words which his Chief of Staff told him on that fateful day.
Bush continued: "Andy Card comes up behind me and says, 'Second plane has hit the second tower. America's under attack'...and I'm watching a child read.
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"Then I see the press in the back of the room beginning to get the same message I just got. I could see the horror etched on the face of the news people who had just gotten the same news."
Speaking about how he dealt with the responsibility of relaying the information to Bush, Card added: "I had to deliver a message that the President didn't expect to hear, and that was almost unbelievable.
"But it also, literally, was the message that he had to hear. Whether he wanted to or not."
Incredibly, Bush managed to keep his cool after finding out that another plane had stuck the World Trade Center just 18 minutes after the first plane hit the north tower.
Apart from a few nervous glances around the room and tightening his grip on a children's book that was in his hands, the former President appeared poised in the face of adversity.
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Revealing how he managed it, Bush said: "During a crisis, it's really important to set a tone and not to panic.
"So I waited for the appropriate moment to leave the classroom - I didn't want to do anything dramatic. I didn't want to lurch out of the chair and scare the classroom full of children, so I waited."
The classroom he was in was later converted into a makeshift command centre, where he even addressed the nation before boarding Air Force One.
Card previously told NBC that it was only at this point, when they were 'well out of harm's way', that the gravity of the situation truly sunk in - and that he had a chance to stew over what he had chosen to tell the President.
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He said: "Obviously, the words I used with the president were grave words. When you say America is under attack, that’s a pretty serious comment to tell the person responsible for protecting the country.
"So I knew the situation was serious - grave - and that there were a lot of things unknown. But nevertheless, I tried to be very, very deliberate and focused and cool, calm and collected.
"Remember, by the time we got on the plane, the attack on the Pentagon had happened, and the plane (Flight 93) was heading towards Washington, D.C.
"We were going through all those emotions. We didn’t know how many victims there were. Estimates were floating around as many as 10,000 people would have died at the World Trade Center and you didn’t know if there were other attacks coming."
Nearly 3,000 people tragically passed away as a result of the September 11 attacks.
Olivia Burke