*Junior Seau was smiling and appeared to be happy at a charity event Monday, possibly his last public appearances before his death Wednesday from a self-inflicted gunshot wound.

People.com has posted the photo from the 18th Annual 911 for Kids Celebrity ProAm Classic, held at the St. Regis Monarch Beach Golf Links in Dana Point, Calif. It shows Seau in a black polo shirt and cap, smiling and apparently relaxed with Karma Tequila co-founder Gary Eisenberger and an unidentified woman.

Event reps say the NFL star was jovial and joked around with other guests as he sipped tequila.

Seau, 43, was deeply involved in charity work, having donated nearly $4 million for services and scholarships to children and young adults. 911 for Kids is an organization dedicated to teaching children about the seriousness of calling 911 and how to properly communicate with emergency operators.

As his friends and family grieve his death, police are investigating it as a suicide.

Junior Seau's mother Luisa Seau

“Monday, Tuesday [he was] talking to me, joking. Junior, why you never tell me?” the legendary NFL linebacker’s mother, Luisa Seau, sobbed in front of her son’s Oceanside, Calif., home on Wednesday – hours after he put a gun to his chest and pulled the trigger.

“I don’t understand, I don’t understand,” Luisa cried. “I prayed to God, ‘Take me. Take me, and leave my son.’ But it’s too late. Too late.”