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.

We got an inside look at the United States Marine Corps' intense 13-week basic training program in San Diego, California.

Narrator: This is Marine Corps boot camp in Parris Island ... Narrator: Recruit training culminates in an event known as the Crucible. Over the course of 54 hours, with minimal sleep and food ...