Former Pro Bowl safety Dave Duerson, who committed suicide Thursday by shooting himself in the chest, sent text messages to family asking that his brain be examined for chronic traumatic encephalopathy. Duerson's family has agreed to to donate his brain to Boston University's medical school for their study of the degenerative disease, which has been tied to depression, dementia and occasionally suicide in the former players, according to The New York Times. "This is a tragic event," Dr. Robert Stern, a co-director of the research group, told The Times. "His wish will hopefully lead to additional scientific answers about this disease."