Chicago Bears defensive end Gaines Adams died Sunday morning after he was taken to a Greenwood, S.C., emergency room, the county coroner said.

Greenwood County Coroner James T. Coursey told ESPN that Adams was taken to the emergency room at Self Regional Hospital, where he was pronounced dead at 9 a.m. ET Sunday morning.

Coursey said the preliminary autopsy performed Sunday indicated Adams died of cardiac arrest caused by an enlarged heart.

"We are stunned and saddened by the news of Gaines' passing," the Bears said in a statement. "Our prayers are with his family during this difficult time."

Adams, 26, listed at 6-foot-5 and 256 pounds, played in college at Clemson and was drafted by the Tampa Bay Buccaneers with the No. 4 overall pick in the 2007 NFL draft. He was traded to the Bears in October.

"I remember him at the 2007 Draft as a fine young man," NFL commissioner Roger Goodell said in a statement. "Our condolences to Gaines' family, his teammates on the Bears and Buccaneers, and their organizations on their loss."

In 47 games over three seasons with the Bucs and Bears, Adams had 67 tackles, including 13.5 sacks.