What you are presenting as facts is actually disinformation. There WERE wing marks and damage on the walls either side. It created a hole approximately 75 ft. wide

First of all, there were numerous witnesses who saw a 737 smash into the building. CNN's coverage of 9/11 live were interviewing witnesses who saw a plane hit the Pentagon.

Second, there is a relatively decent question: why are there no marks where the plane wings hit the building?

The answer is also relatively simple. An airliner, even one like a 737, is comprised of relatively strong, yet also lightweight and thin metal, for the purposes of being able to fly. The idea is to get the strongest body with the least amount of weight. The less the plane weighs, the more passengers you can carry, and the more $$ you can make.

When the plane hit the reinforced concrete walls of the Pentagon, which are quite thick and many times heavier and stronger than the plane body itself, the wings would immediately be sheared off, since the force of the plane's momentum would be spread out over the entire length of the wing, as well as the wall where it hit. Simply put, the wall, being many times more massive, would stay in place, whereas the much less massive wing would be pulverized by the force of the impact. Thus, there would be no wing "marks" on the walls of the Pentagon, in terms of an actual hole or indentation in the side of the building.

How about the hole that the plane fuselage made? Well, again, the wall would still be many times stronger and more massive than the plane itself, however, this time all of the force of the plane's momentum (its mass coupled with the high velocity it was traveling) would all be focused on a relatively small portion of the wall (the circular area that the plane nose hit). In this case, the massive amount of force centered on a very small area caused the wall in that section to give way, allowing for the plane to enter the building as it did.

As I said before, after the nose entered, the plane would advance forward into the building until it was deep enough in that the wings would make contact with the outer walls of the Pentagon. At that point, there would be, in essence, a second "collision" only this time it would the long edge of the wing hitting against a long section of wall. As I explained earlier, the relatively lightweight wing would easily be torn off of the fuselage and destroyed by the force of the impact.

Want to test this simply principle of physics? Here's what you do:

First, punch a wall as hard as you can.

Next, pick up a 2X4 that is about 3 feet long, hold it parallel to the wall, and with the same amount of force, slap it against the wall with the 2X4, making sure that the entire length of the 2X4 makes contact with the length of the wall.

Let me save you some time. Assuming you don't hit a stud and break your forearm with the punch, you'll probably have a nice hole in the drywall where your fist went through, but what you WILL NOT have is a three foot long hole where the piece of 2X4 went through, because it would not.

Not only would the force experienced by every square inch of the wall impacted by the 2X4 be insufficient to cause it to break, but there would also be other wall studs which would absorb the blow and also stop any penetration by the 2X4.

Same principle applies to the Pentagon and the plane wing.

The wing did not exert anywhere near enough force per square inch to cause the Pentagon wall to give way where it hit. It was too spread out over a large area (a 737 wing is LONG) to penetrate the wall.

Having said all that, the plane also exploded on impact, which also explains the lack of a cookie cutter 737 shape in the side of the Pentagon. Go watch the video of the planes hitting the trade centers if you need visual evidence of what a 737 loaded with fuel does when it hits a building.

Taking all of this into account, it is not remarkable at all that there was only a circular hole in the building and no holes where the wings hit.

FACT: When American Airlines Flight 77 hit the Pentagon's exterior wall, Ring E, it created a hole approximately 75 ft. wide, according to the ASCE Pentagon Building Performance Report. The exterior facade collapsed about 20 minutes after impact, but ASCE based its measurements of the original hole on the number of first-floor support columns that were destroyed or damaged. Computer simulations confirmed the findings.

Why wasn't the hole as wide as a 757's 124-ft.-10-in. wingspan? A crashing jet doesn't punch a cartoon-like outline of itself into a reinforced concrete building, says ASCE team member Mete Sozen, a professor of structural engineering at Purdue University. In this case, one wing hit the ground; the other was sheared off by the force of the impact with the Pentagon's load-bearing columns, explains Sozen, who specializes in the behavior of concrete buildings. What was left of the plane flowed into the structure in a state closer to a liquid than a solid mass. "If you expected the entire wing to cut into the building," Sozen tells PM, "it didn't happen."

The tidy hole in Ring C was 12 ft. wide—not 16 ft. ASCE concludes it was made by the jet's landing gear, not by the fuselage.

Intact Windows

Claim: Many Pentagon windows remained in one piece—even those just above the point of impact from the Boeing 757 passenger plane. Pentagonstrike.co.uk, an online animation widely circulated in the United States and Europe, claims that photographs showing "intact windows" directly above the crash site prove "a missile" or "a craft much smaller than a 757" struck the Pentagon.

FACT: Some windows near the impact area did indeed survive the crash. But that's what the windows were supposed to do—they're blast-resistant.

"A blast-resistant window must be designed to resist a force significantly higher than a hurricane that's hitting instantaneously," says Ken Hays, executive vice president of Masonry Arts, the Bessemer, Ala., company that designed, manufactured and installed the Pentagon windows. Some were knocked out of the walls by the crash and the outer ring's later collapse. "They were not designed to receive wracking seismic force," Hays notes. "They were designed to take in inward pressure from a blast event, which apparently they did: [Before the collapse] the blinds were still stacked neatly behind the window glass."

Flight 77 Debris

Claim: Conspiracy theorists insist there was no plane wreckage at the Pentagon. "In reality, a Boeing 757 was never found," claims pentagonstrike.co.uk, which asks the question, "What hit the Pentagon on 9/11?"

Aftermath: Wreckage from Flight 77 on the Pentagon's lawn—proof that a passenger plane, not a missile, hit the building. (Photograph by AP/Wide World Photos)

FACT: Blast expert Allyn E. Kilsheimer was the first structural engineer to arrive at the Pentagon after the crash and helped coordinate the emergency response. "It was absolutely a plane, and I'll tell you why," says Kilsheimer, CEO of KCE Structural Engineers PC, Washington, D.C. "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." Kilsheimer's eyewitness account is backed up by photos of plane wreckage inside and outside the building. Kilsheimer adds: "I held parts of uniforms from crew members in my hands, including body parts. Okay?"