This undated photo provided Dec. 3, 2010, by Erin Birge shows Nathan Stiles. Earlier this year the 17-year-old high school linebacker had an apparent concussion, so he was barred from the field. Over the more than two weeks that followed, doctors and coaches watched him carefully for signs of trouble, letting him suit up only when he showed no clear signs of trouble. Stiles died last month of an undetected subdural hematoma, an apparent re-bleed of the first injury. Now, family, school and medical experts are left wondering if anything more could have been done, and how to prevent a similar tragedy. (AP Photo/Erin Birge)
Read the article: Kansas football player's death points to screening limits
