Fun and easy to prove you wrong with facts. You should try posting facts sometime.
As you can see the FBI took over the crime scene on Sept. 21, then estimated the crime scene investigation would take a month. The FBI ended the crime scene investigation on Sept. 26, if you do the math thats 5 days.
http://www.defenselink.mil/news/newsarticle.aspx?id=44840
The FBI assumed crime-scene jurisdiction at the Pentagon terrorist attack site Sept. 21 from the Arlington County (Va.) Fire Department, officials said.
FBI officials estimate the crime scene investigation would last about a month, Arlington Fire Chief Edward P. Plaugher said. He said he expects "additional remains will be discovered during the course of the FBI investigation" and mortuary specialists will remain on site to process them.
http://www.defenselink.mil/news/Sep2001/n0..._200109266.html
WASHINGTON,
Sept. 26, 2001 -- The FBI handed over Pentagon crash site management to the Army Military District of Washington at 7 a.m. today.
The transfer of responsibility marks the end of the FBI's crime scene investigation following the Sept. 11 terrorist attack against the Pentagon.