We're told Glenn was in a single-car accident early Monday morning and was ejected from his vehicle. By the time officials responded to the crash site, it was clear Glenn had passed. He was pronounced dead on arrival.

Glenn had a passenger in his vehicle -- we're told it was his fiancee -- but she survived the crash. She's currently being treated at the ICU of a local hospital.

We're told officials plan on doing a full autopsy, including toxicology, to see if they can get more information on what led to the crash.

Glenn was the 7th overall pick in the 1996 NFL Draft -- taken by the New England Patriots after an impressive run at Ohio State.

He went on to play 12 seasons in the NFL -- with the Patriots, Packers and Cowboys.

Terry also famously caught Tom Brady's very first TD pass in 2001.

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