Junior Seau's suicide adds him to a growing list of NFL players who have struggled after their careers. (AP)

Junior Seau’s death has provoked many people who knew him and many more who didn’t to celebrate his admirable qualities.

He loved the game he played, and he inspired those who played beside him. What pro athletes admire most in their peers is longevity, and Junior Seau certainly achieved that. The average NFL career lasts a couple of years. Seau played from 1990 until 2009.

He was dedicated to achieving excellence through hard work. According to some of his former teammates in New England, the trainers in the Patriots weight room complained about how early Seau would arrive to begin his workouts.

He was a thoughtful friend. Robert Kraft, the owner of the team for which Seau last played, spoke this week about how touched he was by a note Seau wrote him when Kraft’s wife passed away.

But although many of those who thought they knew him best have said they saw no indication that he would kill himself, that is what Seau did. In so doing, he joined the many ex-NFL players whose deaths have provoked serious concern about the damage done in the workplace they chose. This means that those celebrating the life of Junior Seau cannot be content with celebration. They must also consider the relationship of his loss to the daily business of the game in which he so impressed them and distinguished himself.

Like Dave Duerson in February of 2011, Seau shot himself in the chest. Duerson left a note directing that his brain should be examined by those investigating chronic traumatic encephalopathy, the concussion-related condition that has been present in the brains of other ex-NFL players who have killed themselves or otherwise died prematurely. No such note has been found where Seau died, but his family has indicated that his brain will be made available for study.

The list of ex-NFL players who have killed themselves or died in bizarre accidents or suffered from dementia, memory disfunction, and depression grows, as does the number of ex-players currently suing the National Football League. About 1500 former players have joined those suits, which contend that the league has consciously failed to protect the health and welfare of the players, despite knowing of the damage being done to the brains of those players engaged in their work. The league denies those charges.

Junior Seau was 43 years old. The results of the examination of his brain will probably be available in four to six weeks.