In an unassuming building in suburban Washington, a team of military medical specialists spent six months poring over autopsies of 4,016 men and women who had died on the battlefields of Iraq and Afghanistan.

They read reports from the morgue at Dover Air Force Base, where bodies arrived in flag-draped coffins. They examined toxicology reports. They winced at gruesome photos of bullet wounds and shredded limbs. In each case, the doctors pieced together the evidence to determine the exact cause of death.

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