Not long after the initial reports of Seau's death, past and present NFL players shared their love and support for him and his family on Twitter. Many tweeted their condolences and some shared stories about the linebacker who was often looked to as a role model.
Seau, the 1994 recipient of the Walter Payton Man of the Year award, is widely considered to be a first-ballot Hall of Famer and will be eligible in 2015.
One of the most dominant linebackers ever to play at USC, Seau helped lead the Trojans to back-to-back Rose Bowls and won the 1989 Pac-10 Defensive Player of the Year Award. He was inducted into the USC Hall of Fame in 2009.
Seau was drafted by the Chargers with the fifth overall selection in the first round of the 1990 NFL draft. He went on to play in the NFL for 20 years, 13 seasons with the San Diego Chargers, three with the Miami Dolphins and four with the New England Patriots. He was selected the Pro Bowl 12 years in a row, was named First-Team All-Pro six times and played a crucial role for the 1994 Chargers team that went to the Super Bowl.
Linebacker Junior Seau of the San Diego Chargers looks on during a game against the Los Angeles Raiders at the Coliseum in Los Angeles, California. The Raiders won the game, 34-7.
San Diego Chargers Junior Seau tackles Pittsburgh Steelers Ernie Mills during the first quarter of their AFC Championship game in Pittsburgh's Three Rivers Stadium. The Chargers defeated the Steelers 17-13 to advance to the Super Bowl.
San Diego Chargers' Junior Seau, right, congratulates San Francisco 49ers quarterback Steve Young after the 49ers 49-26 victory in Super Bowl XXIX at Miami's Joe Robbie Stadium.
Shannon Sharpe, #84 of the Denver Broncos, carries the ball as he is tackled by Junior Seau of the San Diego Chargers at the Mile High Stadium in Denver, Colorado. The Broncos defeated the Chargers 30-27.
Linebacker Junior Seau of the San Diego Chargers sits on the bench during the Chargers 27-14 victory over the Cincinnati Bengals at Jack Murphy Stadium in San Diego, California.
Miami Dolphins linebacker Junior Seau tackles for the ball at Pro Player Stadium, Miami, Florida on September 7, 2003. The Houston Texans defeated the Dolphins 21 - 20 to open the NFL football season.
Miami Dolphins linebacker Junior Seau is a blur of motion entering the field at Pro Player Stadium. The Dolphins defeated the Atlanta Falcons 30 - 21 in a pre-season game.
Football linebacker Junior Seau speaks to fans and the media during a news conference announcing his retirement from pro football, at the Chargers' training facility in San Diego. Seau retired after 13 seasons as the live-wire leader of his hometown San Diego Chargers and three less-productive years with the Miami Dolphins, four days before coming out of retirement to sign with the New England Patriots.
New England Patriots' head coach Bill Belichick, right, talks to linebacker Junior Seau during second half NFL football action against the New York Jets in East Rutherford, N.J.; Patriots won, 38-14.
New England Patriots linebacker Junior Seau holds the Lamar Hunt Trophy looks on after defeating the San Diego Chargers 21-12 in the AFC Championship NFL football game in Foxborough, Mass.
Linebacker Junior Seau, left, rides the Zamboni between periods of the Boston Bruins NHL hockey game against the Washington Capitals in Boston, before resigning with the pats for his 20th season in the NFL.
Junior Seau, right, butts heads with teammate linebacker Pierre Woods in the snow prior to an NFL football game against the Tennessee Titans at Gillette Stadium in Foxborough.
An SUV belonging to Junior Seau, hauled onto a truck after it was driven off an embankment in Carlsbad, Calif. Seau was hospitalized with minor injuries, and denied that the incident was an attempt of suicide.
Former San Diego Chargers great Junior Seau smiles during his induction into the Chargers Hall of Fame during a halftime ceremony of an NFL football game in San Diego.