Posted by Sabrina B. @gametimegirl

The death of former Chicago Bears safety Dave Duerson was ruled a suicide by the Miami-Dade County Medical Examiner, WMAQ-TV in Chicago reported Saturday.

Duerson was found dead Thursday night at his home in Miami. The Miami-Dade County Medical Examiner said he died from a gunshot wound to the chest.

In a text message he sent to loved ones before his death, Duerson asked that his brain, particularly the “left side,” be left for NFL researchers who study chronic traumatic encephalopathy (CTE), a degenerative disease common to boxers, football players and others who experience multiple concussions and head injuries.

“NFL players are at high risk for CTE,” said Chris Nowinski, co-director of the Center for the Study of Traumatic Encephalopathy at Boston University School of Medicine.

Nowinski said Duerson donating his brain for study was “an incredible selfless contribution to medical research.”

Duerson, 50, starred at Notre Dame and played for the legendary Bears defense that powered the team to a victory in Super Bowl XX. He was elected to four straight Pro Bowls from 1986-89 and also won a second Super Bowl with the 1990 Giants.

The news of Duerson’s untimely death was met with shock from his former Bears teammates.

“When we spoke recently, he sounded great,” former Bears defensive back Shaun Gayle said. “It’s a real shock to all of the guys.”

Duerson set a record — later broken by Cardinals safety Adrian Wilson in 2005 — for most sacks in a single season by a defensive back, with seven.

“He was a hell of a football player,” former Bears coach Mike Ditka said Friday. “He came in at the right time for us because that’s when Todd Bell held out. He fit right in, became a starter. We liked everything about him at Notre Dame. He rounded out that defense. He fit in perfectly with Gary Fencik back there and was one of the leaders of our team.”

Duerson is survived by four children.