OCEANSIDE, Calif. -- Police in Oceanside, Calif., say the death of former NFL star Junior Seau appears to be a suicide.

Seau, who was 43, was found shot to death at his home today. Police say his girlfriend reported finding him unconscious with a gunshot wound to the chest. A gun was found nearby.

His mother, Luisa Seau, was weeping uncontrollably as she appeared before reporters. She said, "I don't understand." She said her son had given no indication of a problem when she spoke to him by phone earlier in the week, and that he was "joking" with her.

Seau was a standout linebacker with USC before going to the San Diego Chargers and leading them to the Super Bowl after the 1994 season. The team says in a statement that everyone with the Chargers "is in complete shock and disbelief" over the news.

In October of 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 home he shared with his girlfriend. She had told authorities that he assaulted her during an argument.

Seau told authorities he fell asleep while driving. He suffered minor injuries.