Me - Drowning
Amy - Shot herself
Tails - Plane crash
Knuckles - Dropped weights on his head because he saw a butterfly
Sticks - Nuclear explosion
Eggman - Drugs
Kelsey, Shadow and Maria - hanged themselves
Silver - Was in a wild fire
Perci - Car accident
Zooey - Jumped off a cliff
Sora and Rosalina - Stillbirths{Not really now kill me.}
"I'm changing Rosalina's name."