Ari Fleischer with President George W. Bush on September 11, 2001.
Fleischer said he took detailed notes that day and many of his postings include him directly quoting the president.
"We're at war, Dick, and we're going to find out who did this and we're going to kick their ass," Bush, who was in Florida, told Vice President Dick Cheney in one of their first phone calls after the attack.
Along with specific conversations, Fleischer revealed other details about the day including that officials were apparently afraid high-level members of the U.S. government could have been involved in the attacks.
Bush began the day at an elementary school in Florida where he was holding an event where he planned to discuss education. Fleischer said the Secret Service was reluctant to have Bush return to Washington because they believed "Andrew(s) Air Force Base and the White House could be targets."
According to Fleischer, an anonyous caller to the White House switchboard warned "Angel is next." Angel was the codeword for Air Force One, which Fleischer said made those on board worry there was "an inside attack." Fleischer said the plane's pilot received warnings the president's plane may have been targeted by snipers or another plane as it left Florida.
"A call came into the switchboard saying 'Angel is next,'" Bush said. 'Angel' was the codeword for Air Force One.
- Ari Fleischer (@AriFleischer) September 11, 2014
Think about that. Aboard one of the most secure spots on earth, with nothing but trusted aides/Secret Service, the fear was an inside attack
- Ari Fleischer (@AriFleischer) September 11, 2014
According to Fleischer officials
Fleischer's tweets included a photo of notes he took that day. Based on the notes, about ten minutes after the second World Trade Center tower collapsed, Bush was told his daughters were removed to a "safe house." Bush responded by asking about his dog, Barney. Fleischer quoted former White House Chief of Staff Andy Card responding by saying the dog was, "nipping at the heels of Osama bin Laden."
Here is a copy of one page from my notes while all this was going on: pic.twitter.com/xpqWXWLMAQ
- Ari Fleischer (@AriFleischer) September 11, 2014
Fleischer also tweeted photos of the president that day and other unique shots including a picture of a "Doomsday plane" that could have been used to launch nuclear strikes, and the outside of "a small non-nondescript building that led all the way down to a command bunker" where the president met with advisors.
3:10 We landed at Offut Air Force Base & parked next to a Doomsday plane. They used to be in the sky 24/7 to order nuke strikes if needed.
- Ari Fleischer (@AriFleischer) September 11, 2014
Here's what a Doomsday plane looks like. It was eerie just to see it, especially that day. pic.twitter.com/OkDsNqxi8b
- Ari Fleischer (@AriFleischer) September 11, 2014
Here is a scene aboard AFOne in POTUS's cabin, enroute Barksdale. pic.twitter.com/ayAgN7Efuv
- Ari Fleischer (@AriFleischer) September 11, 2014
Here is the scene as we entered a small non-nondescript building that led all the way down to a command bunker. pic.twitter.com/i66H0jzPgh
- Ari Fleischer (@AriFleischer) September 11, 2014
Here is the building. The press was not allowed in, but they could film the "building". pic.twitter.com/0jw7Id6t1n
- Ari Fleischer (@AriFleischer) September 11, 2014
One of the more interesting things about Fleischer's tweets is they show how much harder it was for the president to remain in touch and informed in the pre-smartphone era.
Approx 8:50: I got a page on my pager (we didn't have blackberries then and the iPhone hadn't been invented) telling me a plane hit the WTC.
- Ari Fleischer (@AriFleischer) September 11, 2014
Someone wheeled a TV into the holding room. Here's the scene: pic.twitter.com/x9A3RTQykd
- Ari Fleischer (@AriFleischer) September 11, 2014
The TVs aboard AFOne could only pick up signals as we flew over land areas with good signals. The transmissions kept coming in and out.
- Ari Fleischer (@AriFleischer) September 11, 2014
After 9/11, we recognized that the technology needed a major upgrade. In terms of communications, AFOne today is unlike how it was on 9/11.
- Ari Fleischer (@AriFleischer) September 11, 2014
Fleischer, who did not respond to an email from Business Insider asking about his livetweeting, is still going. You can read all his tweets here.