Firemen and FBI agents shelter behind barricades as flames rip through the Pentagon, unsure if another attack is about to come.
Overhead shots show the extent of the devastation and pictures from the investigation show dozens of FBI agents picking through the debris as they collect evidence.
About 189 people died when the plane crashed into the Pentagon on 9/11, when terrorists also flew planes into the World Trade Centre in New York.
Of the 189 who died at the Pentagon, 125 worked at the facility, which is a short distance from the White House in Washington D.C.
Flight 77 struck between the first and second floor of the Pentagon and created a hole about 6m wide and 30m deep.
It penetrated three outer rings of the building as the Boeing 757 travelled 95m in less than a second.
The devastation was staggering and caused part of the Pentagon to collapse; it took days for firefighters to extinguish the blaze because it was so intense.
The 27 images were uploaded to the FBI website with the headline "9/11 Attacks and Investigation Images" and no further details.
The images have a range of titles including "9-11 Pentagon Debris", "9-11 Pentagon Exterior" and "9-11 Pentagon Emergency Response".
The debris photos appear to show sections of the plane, including a piece of metal that has been sheared off and one that appears to be part of the fuselage where the letter "c" from American Airlines is clear.
Another shows a gold-coloured piece of metal with a number on the side, and an American Airlines logo.
A powerful image taken directly in front of where the plane went in shows the building looking black and charred. Fire engines on both sides spray water on the smouldering structure.
Photos from the weeks after the attacks show massive concrete chunks and mangled wires on the exterior of the Pentagon at the impact zone.
Shots from inside show a circular hole 4m wide by 4m tall that has been blasted through a brick wall.
The pictures show FBI investigators carrying debris with wheelbarrows and sifting by hand through piles of wood and bricks.
All are wearing hard hats, protective goggles and gas masks because of the fumes.
Other FBI agents are in full body suits to protect them from toxic materials.
The images are likely to be seized on by conspiracy theorists, some of whom who contend there was never actually a plane crash at the Pentagon.
A widely circulated animation on Pentagonstrike.co.uk showed that windows right above the impact zone were intact, which was supposedly evidence that a missile hit the Pentagon and not a plane.
Others have raised questions over how the plane fit through such a small hole given that it had a wing span of more than 35m.
One of the most thorough analyses of conspiracy theories about 9/11, by Popular Mechanics, debunked all claims that deviated from the 9/11 Commission findings.
To those who claimed there was never any wreckage at the scene, they quoted blast expert Allyn E. Kilsheimer, who was the first structural engineer to arrive at the Pentagon after the crash.
Kilsheimer, who is chief executive of KCE Structural Engineers PC in Washington, D.C. said: "I saw the marks of the plane wing on the face of the building. I picked up parts of the plane with the airline markings on them. I held in my hand the tail section of the plane, and I found the black box.
"I held parts of uniforms from crew members in my hands, including body parts. Okay?"
Some of the FBI images appear to have been published on conspiracy theory and government secret websites in 2011 but were not widely circulated before the latest release.
The damaged sections of the Pentagon were rebuilt in 2002 and in August that year staff moved back in.
A half-hectare memorial garden for the victims was completed in 2008 close to the Pentagon and contains a bench for each of the victims.
DailyMail.com has asked the FBI for comment.
