Colleagues of Renee Royak-Schaler at the University of Maryland School of Medicine paid for and conducted an autopsy that revealed that cancer had ravaged her body. Today, autopsies are conducted on just 5 percent of patients. Jenna Isaacson Pfueller/ProPublica hide caption

itoggle caption Jenna Isaacson Pfueller/ProPublica

Sgt. Victor Medina suffered brain damage in 2009 when a roadside bomb exploded in Iraq. Blake Gordon/Aurora Photos hide caption

itoggle caption Blake Gordon/Aurora Photos

Unlike the medical examiner's office in New Mexico, which routinely autopsies sudden or violent deaths, most U.S. hospitals perform postmortem examinations only rarely. John W. Poole/NPR hide caption

itoggle caption John W. Poole/NPR

Dr. Alex Dromerick co-directs the Brain Research Center at the National Rehabilitation Hospital. Here he observes Stephen Jones, a policeman who was involved in a motorcycle accident. Becky Lettenberger/NPR hide caption

itoggle caption Becky Lettenberger/NPR

Jeff Galemore leans on his pickup truck near the Ash Grove Cement plant in Chanute, Kan. He and his family are concerned about the toxic emissions and are fighting for independent testing downwind. David Gilkey/NPR hide caption

itoggle caption David Gilkey/NPR

The Continental Carbon plant sits on the southern outskirts of Ponca City, Okla. Until August, the plant was on an internal EPA "watch list," for violating rules of the Clean Air Act. David Gilkey/NPR hide caption

itoggle caption David Gilkey/NPR

The Continental Carbon plant sits on the southern outskirts of Ponca City, Okla. Residents blamed the plant, which produces a black dust known as carbon black, for polluting their city. David Gilkey/NPR hide caption

itoggle caption David Gilkey/NPR