Police Lt. Karen Laser confirmed the death. U-T San Diego reported that a 911 call came from the home at 10 a.m.
Seau was a standout linebacker with the University of Southern California before going to the San Diego Chargers, whom he led to the Super Bowl following the 1994 season.
“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.
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.
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.