The San Diego County medical examiner's office has ruled Junior Seau's death a suicide.

The autopsy says the former San Diego Chargers linebacker died Wednesday of a gunshot wound to the chest. The medical examiner's office says it is awaiting a decision by the family on whether to turn over Seau's brain to unidentified outside researchers for study.

His ex-wife told The Associated Press on Wednesday that Seau sustained concussions during his 20-year career. Seau's death follows the suicide last year of former Chicago Bears player Dave Duerson, who also shot himself in the chest.

Meanwhile, more than 100 former NFL players have filed a federal lawsuit in Atlanta claiming that pro football didn't properly protect its players from concussions.

The plaintiffs in the lawsuit include former Atlanta Falcon Jamal Anderson, ex-Georgia star Lindsey Scott and veteran quarterback Don Majkowski.

They are among more than 1,000 former players suing the league because they don't think the NFL did enough to inform players of the dangers of concussions.

The NFL has said any allegation that the league intentionally sought to mislead players is without merit.