Investigations

Sgt. Victor Medina suffered brain damage when an IED hit his truck in Iraq. Even after he was diagnosed with a traumatic brain injury, he found he had to fight to get adequate care. Blake Gordon/Aurora Photos hide caption

Michelle Dyarman, a former major in the Army reserves, was involved in two roadside bomb attacks and a Humvee accident in Iraq in 2005 that left her with serious cognitive problems. David Gilkey/NPR hide caption

Clay Mullins (left), brother of mine disaster victim Rex Mullins, listens as Upper Big Branch miner Stanley "Goose" Stewart tells the House Education and Labor Committee that the mine "was a ticking time bomb" because of problems with ventilation and explosive methane and coal dust. Jon C. Hancock/AP hide caption

A Mexican soldier stands guard as a haul of marijuana and cocaine are incinerated in the background in November 2009. Fighting among the drug cartels — and between government forces and the cartels — has cost nearly 24,000 Mexican lives since late 2006. Jesus Alcazar/AFP/Getty Images hide caption

The Santa Fe bridge (shown in February 2010) links the Mexican city of Ciudad Juarez (bottom) with the U.S. city of El Paso in Texas. American law enforcement officials say they are worried that violence from newly Sinaloa-controlled areas of Ciudad Juarez will spill over into the U.S. Alexandre Meneghini/AP hide caption

Mine workers stand at the entrance of the Upper Big Branch coal mine on April 9, a few days after an explosion killed 29 men. Matt Sullivan/Getty Images hide caption