More than two dozen U.S. commandos carried out the raid on Osama bin Laden's compound in Pakistan.
The identities of the men who were apart of it may never be known.
They were members of SEAL Team Six.
To clarify, there's a unit called Navy SEALS, and then there is SEAL Team Six. They are not the same.
Eric Greitens is a Navy SEAL. He made it through a grueling six-month course in California, where some two-thirds of candidates fail.
Then he was sent to Afghanistan as a member of that elite unit, hunting down al-Qaida fighters.
Challenging enough, but Greitens says the commandos who slipped into bin Laden's compound are a cut above.
"They are experienced operators, who have years under their belts conducting operations in Iraq and Afghanistan. They are really the very best of the best," Greitens says.
And the best of the best, he says, is SEAL Team Six, the anti-terrorist unit created three decades ago. They are selected from the talent pool of SEAL operatives, after they've spent years on the job.
Then six more months of training as part of what's called the Green Team. They practice clearing a room of enemy fighters, parachuting from high altitudes and boarding ships in stormy seas. Only about half of those who apply make the team.
One who did was Ryan Zinkie, who spent a dozen years as a member of SEAL Team Six. Part of that time, he spent in the Balkans during the 1990s tracking down suspected war criminals.
"Our mission was to, at that point in time, was really to capture."
When asked how many he captured, Zinkie answers "a few" and then laughs.
If Zenkie sounds cocky, he says that's kind a Team Six spirit.
"There's an air, I don't want to say arrogance, but to a degree, they understand who they are, they understand the level of commitment to get to be who they are, and they understand they represent the best in the world," Zinkie says.
Admiral Bob Natter commanded the Atlantic Fleet nearly a decade ago. He was familiar with Team Six missions. To this day, he won't talk about them in detail.
"Many of those operations are quick response. Some of them, they're able to train for," Natter says.
Train by building an exact replica of their target site. In the case of bin Laden, a compound and its two buildings.
Former Team Six member Zinkie says they would practice the assault over and over at a secret location.
"They have a number of sites throughout the U.S. that are tucked out of the way," he says.
Then the team would put together a detailed list of everything that happens on the mission: When a helicopter lands. When they enter the target area. Each movement labeled with a specific time.
"In this operation, considering how complex it was, there were probably 40 pages of execution check-list calls and time-frames," Zinkie says.
The mission this week was over in less than 40 minutes. Ending with the codeword for bin Laden and his fate: Geronimo EKIA — Enemy Killed in Action. Copyright 2011 National Public Radio. To see more, visit http://www.npr.org/.