OCEANSIDE, Calif. - Former NFL star Junior Seau 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.

"We believe it was a suicide," said Oceanside police Lt. Leonard Mata. "There is no indication of foul play."

Seau's mother appeared before reporters, 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 was a standout collegiate linebacker at Southern California before going to the San Diego Chargers - his hometown team - whom he led to the Super Bowl following the 1994 season. He was voted to a team-record 12 straight Pro Bowls and was an All-Pro six times in a career that lasted two decades.

"Everyone at the Chargers is in complete shock and disbelief right now. We ask everyone to stop what they're doing and send their prayers to Junior and his family," the team said in a statement.

"It's a sad thing. It's hard to understand," said Bobby Beathard, who as Chargers general manager took Seau 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.

"He was a leader emotionally and he played that way," Beathard said. "He was great to young kids. I just can't imagine this, because I've never seen Junior in a down frame of mind. 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."

Seau 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.

Seau's also is among a few recent, unexpected deaths of NFL veterans.

In February 2011, ex-Chicago Bears player Dave Duerson shot himself in the chest. His family has filed a wrongful death suit against the NFL, claiming the league didn't do enough to prevent or treat concussions that severely damaged Duerson's brain before he died.

Former Atlanta Falcons safety Ray Easterling, who had joined in a concussion-related lawsuit against the league - one of dozens filed in the last year - died last month at age 62. His wife has said he suffered from depression and dementia after taking years of hits.

Seau, however, is not known to have been a plaintiff in the concussion litigation.

Seau remained with the Chargers until 2003 and went on to play with the Miami Dolphins and New England Patriots before retiring after the 2009 season. He amassed 545 tackles, 56 1/2 sacks and 18 interceptions in his career.

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.

More than 100 people gathered outside of Seau's home, only hours after he was found dead. Families showed up with flowers and fans wearing Chargers jerseys waited to get more news.