Former White House press secretary Ari Fleischer was there in the Florida classroom where George Bush first learnt the country was under attack.

He flew on Air Force One as it completed Cold War-era random flying manoeuvres to avoid threats. He was in the command bunker as Mr Bush ran a National Security Council meeting. 

Now, 13 years later, he has tweeted a detailed account of that day - the fear, the misinformation and the search for safety. 

In messages timed to coincide with the original events, Mr Fleischer discusses everything from military to media responses.

The consultant reveals the suspicions that Air Force One was facing attack from within and without. He details how the plane made an unusually steep ascent to avoid an anticipated sniper attack.

He tells of Mr Bush's first reactions to the tragedy and his private vows of revenge.

Here is a selection of messages from Mr Fleischer's account.