Englewood, Colorado - The NFL and football fans are mourning the loss of former wide receiver Demaryius Thomas, who passed away suddenly on Thursday.

Thomas (33), who had the most professional success as a member of the Denver Broncos, died on Thursday in his home of an apparent medical emergency.

He was found by the local police department in Roswell, Georgia.

ESPN first broke the story late Thursday night, but LaTonya Bonseigneur, a first cousin of Thomas told the Associated Press that the family believes he had succumbed to a seizure.

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"He had been suffering from seizures for over a year, and we believe he had a seizure when he was showering," Bonseigneur said. "We're not sure when he died. We just spoke with him yesterday."

Thomas started his NFL career with the Broncos after being drafted out of Georgia Tech in 2010. After a successful career in Denver, he then went on to play for the Texans, Patriots, and Jets before retiring from the NFL in June of this year.

But it was in Denver where he experienced the most success, finishing his career as the team's second-leading receiver (9,055 yards), behind only Rod Smith and third in catches (655) behind Smith and Hall of Famer Shannon Sharpe, respectively.

Thomas also helped the Broncos get to two AFC Championship games during his nine years with the team and ultimately the big game, winning Super Bowl 50 over the Panthers in 2016.

Current and former NFL stars took to Twitter to express their grief at the shocking news, including the Bucs' Tom Brady and Thomas' former teammate DeMarcus Ware.

Demaryius Thomas finished his career on 724 catches, 9,763 yards, and 63 touchdowns, having been named to five Pro Bowls.