Narrator: This Marine Corps recruit isn't actually injured ... Narrator: It's part of their final test at boot camp, known as the Crucible, a 54-hour event that all recruits must complete.

drill instructor blows whistle] These recruits are 36 hours away from officially becoming United States Marines ... during their final challenge of boot camp, a 54-hour gauntlet called the ...

Brooklier, 29, enlisted in the Marine Corps in January ... Toward the end of boot camp, Brooklier finally got to do the Crucible. And it was indeed challenging, both physically and mentally ...