Gaines Adams, an All-American defensive end at Clemson whose career never blossomed in the NFL with Chicago and Tampa Bay, died Sunday after going into cardiac arrest. He was 26. He died at Self Regional Hospital after going into cardiac arrest about an hour before at his family’s home in Greenwood, said Marcia Kelley-Clark, chief deputy coroner for Greenwood County. An autopsy showed an enlarged heart, a condition that can often lead to a heart attack, Kelley-Clark added. She said relatives were unaware of any medical condition. Toxicology tests are being run by the State Law Enforcement Division, though drug use is not suspected. The results probably will not be available for at least two months. Adams, six-foot-five and 258 pounds, spent three seasons in the NFL, two with the Buccaneers and part of this season with the Bears. Adams was selected fourth overall in the 2007 draft by Tampa Bay. He had not been able to live up to expectations that he would revive the Buccaneers’ once-feared pass rush, and had just 17 tackles and one sack in 15 games this season. He was traded to the Bears in October for a second-round pick in the 2010 draft. “Gaines was a quiet, humble kid and is far too young to be gone,” Buccaneers cornerback Ronde Barber said.