GREELEY, Colo. -- The mangled pieces are set up to simulate the impact point of Saturday's deadly plane crash in Boulder.

The Piper Pawnee's wooden propeller sits in the front of the garage at Beegle's Aviation in Greeley.

Most of the Cirrus SR 20 was burned as it fell to the ground Saturday, killing brothers Bob and Mark Matthews.

"We have noted quite a bit of crushing," said Jennifer Rodi, lead investigator with the National Transportation Safety Board. "This is as close as it’s going to get. We’re just going to go through the different systems, the different areas and see if we can find any other evidence of paint transfer."

Unlike other crashes, which revolve around parts or computer systems, there are no suspected mechanical contributors, Rodi said.

There are pieces of metal where the blue paint of the Cirrus is still embedded onto the Piper.

The SR20's prop is bent back, from the sheer force of the impact at 8,300 feet.

Rodi said investigators had already removed gruesome pieces of evidence, such as clothing and body parts from the wreckage and would now try to look at what was left to get a mental image of the 90-degree angle that formed the impact point.

Beyond that, Rodi said, the investigation into what happened will rely heavily on witness statements.

"You have to do a lot more touchy-feely type of supposition and theory. You know how the human eyeball works, you know how the brain works, you know hearing works. And then taking that into consideration, you can’t fill in the blanks because you can’t ask the pilots what they were doing," Rodi said.

Rodi said the final conclusion on the crash wouldn't be available for up to 10 months but also said pilot error is one factor that will be examined.