What it takes to be a sentinel at the Tomb of the Unknown Soldier

Source: Business Insider

To become a sentinel at the Tomb of the Unknown Soldier in Arlington National Cemetery, Army soldiers must endure a six-to-nine-month training program that 90% of trainees do not complete. The sentinels say they're constantly chasing a standard of perfection. No one feels that more than 19-year-old Pvt.