Rare photos of 9/11 Pentagon wreckage

 On Sept. 11, 2001, al-Qaida terrorists hijacked and flew American Airlines flight 77 into the western side of the Pentagon, killing 189 people — 125 victims in the building, 59 on board the flight and the five perpetrators. More than 15 years after the attack, the Federal Bureau of Investigation (FBI) released never-before-seen photos of the Pentagon following the attacks. Here is a look at some of those images. 

 The Boeing 757 damaged an entire section of the Pentagon — killing 70 civilians and 55 military personnel inside the building. 

 Fortunately, at the time the building was undergoing renovation and many of the offices were unoccupied. 

The impact caused the outer ring of the western wing of the building to collapse. 

 Fire engulfed the entire section as firefighters fought to handle the blaze that started when the plane crashed into the three outermost rings. 

 Hundreds of firefighters managed to finally control the blaze. 

 The section of the building that was struck housed the Naval Command Center. 

 Heavy machinery was brought onsite to clear the debris. 

 Clean-up work at the damaged section went on through the night. 

A sea of tents came up around the area as makeshift operations were set up to start 
investigations. 

 Investigators went into the building to inspect the charred remains. 

 The ensuing FBI investigation was code-named "PENTTBOM" and more than half the field agents were involved in the investigation. 

 The site was one of the largest crime scenes in FBI history. 

 The FBI Evidence Response Team (ERT) worked on their largest-ever investigation. 

 Forensic specialists (whose identities were not released) investigated the attacks. 

 Canine teams were also called in to investigate the wreckage. 

 Components of the Boeing 757 were found scattered through the debris. 

 What appeared to be a part of the plane's fuselage was also recovered. 

 The rebuilding of the damaged section was named "Project Phoenix."

A melted photocopier seen in one of the offices. 

 Once the firefighters were through, the scope of the damage was finally seen.

 This undated photo provided by the FBI shows damage to the Pentagon caused during the 9/11 attacks. The FBI released a group of photos on March 30, 2017, showing the aftermath of the crashing of the hijacked American Airlines Flight 77 into the Pentagon.

 This undated photo provided by the FBI shows damage to the Pentagon caused during the 9/11 attacks.

 Washington Field Office Evidence Response Team members at the Pentagon shortly after the attack on 9/11.

 Debris from the 9/11 attacks on the Pentagon. 

Rescue personnel raised the American flag on top of the building after the attack.