(AP) - Junior Seau, a homegrown superstar who was the fist-pumping, emotional leader of the San Diego Chargers for 13 years, was found shot to death at his home Wednesday morning in what police said appeared to be a suicide. He was 43. Police Chief Frank McCoy said Seau's girlfriend reported finding him unconscious with a gunshot wound to the chest and lifesaving efforts were unsuccessful. A gun was found near him, McCoy said. Police said no suicide note was found and they didn't immediately know who the gun was registered to. Seau's death in Oceanside, in northern San Diego County, stunned the region he represented with almost reckless abandon. The same intensity that got the star linebacker ejected for fighting in his first exhibition game helped carry the Chargers to their only Super Bowl, following the 1994 season. A ferocious tackler, he'd leap up, pump a fist and kick out a leg after dropping a ball carrier or quarterback. "It's a sad thing. It's hard to understand," said Bobby Beathard, who as Chargers general manager took Seau out of Southern California with the fifth pick overall in the 1990 draft. "He was really just a great guy. If you drew up a player you'd love to have the opportunity to draft and have on the team and as a teammate, Junior and Rodney (Harrison), they'd be the kind of guys you'd like to have." Quarterback Stan Humphries recalled that Seau did everything at the same speed, whether it was practicing, lifting weights or harassing John Elway. "The intensity, the smile, the infectious attitude, it carried over to all the other guys," said Humphries, who was shocked that Seau is now the eighth player from the '94 Super Bowl team to die. Seau's mother appeared before reporters outside the former player's house, weeping uncontrollably. "I don't understand ... I'm shocked," Luisa Seau cried out. Her son gave no indication of a problem when she spoke to him by phone earlier this week, she said. "He's joking to me, he called me a 'homegirl,'" she said. Seau's death follows the suicide last year of former Chicago Bears player Dave Duerson, who also shot himself in the chest. In October 2010, Seau survived a 100-foot plunge down a seaside cliff in his SUV, hours after he was arrested for investigation of domestic violence at the Oceanside home he shared with his girlfriend. The woman had told authorities that Seau assaulted her during an argument. There was no evidence of drugs or alcohol involved in the crash and Seau told authorities he fell asleep while driving. He sustained minor injuries. "I just can't imagine this, because I've never seen Junior in a down frame of mind," Beathard said. "He was always so upbeat and he would keep people up. He practiced the way he played. He made practice fun. He was a coach's dream. He was an amazing guy as well as a player and a person. This is hard to believe." Seau's ex-wife, Gina, told the Union-Tribune San Diego that he texted her and each of their three children separate messages: "I love you." "We're all in shock," she said. "We're beyond sad and beyond shocked. The kids and I are just huddled together at home. There is no way to make sense of this." Seau, who played in the NFL for parts of 20 seasons, is the eighth member of San Diego's lone Super Bowl team who has died, all before the age of 45. Lew Bush, Shawn Lee, David Griggs, Rodney Culver, Doug Miller, Curtis Whitley and Chris Mims are the others.