Chicago Bears defensive end Gaines Adams died Sunday morning from apparent cardiac arrest, his team announced. Adams was 26.
"We are stunned and saddened by the news of Gaines' passing. Our prayers are with his family during this difficult time," the Bears said in a statement.
Adams, selected by the Tampa Bay Buccaneers in the 2007 NFL Draft, was the fourth overall pick. The Bears acquired Adams in a trade from Tampa last October.
"Health issues" prompted Adams' girlfriend to call an ambulance, County coroner James T. Coursey told the NFL Network. He said that Adams had no history of health problems.
Adams was admitted to the emergency room at Self Regional Hospital at 8 a.m., The Greenville News reported; he was pronounced dead a half-hour later.
A preliminary autopsy indicated that Adams died of cardiac arrest, caused by an enlarged heart, a spokesman for the Greenwood County coroner's office said.