Unfortunately, it's residential bad boy Noah Puckerman. No, not dead on screen.
Mark Salling, who plays Noah Puckerman
Stupid decisions + harmful addiction = depression (?); Depression = Suicide
A little insight news if you didn't know - Mark was arrested in 2015 and charged in 2016 for Child Pornography.
Still, though his character was pretty much an ass & a bully, in real life, he is a "gentle & loving person" as described by family members. He just made some seriously stupid mistakes and I guess the sound of prison didn't digest too well with him.
This is the second death of a 'Glee' star, following Cory Monteith's sad demise in 2013.