Autopsy results revealed Tuesday that 31-year-old "Glee" star Cory Monteith died of a "mixed drug toxicity" that included heroin and alcohol. The death appears to be an accident, according to the British Columbia Coroner's Service in Canada, which is still continuing the investigation.

Monteith was found dead on Saturday night in his Vancouver hotel room. With what many are considering an extremely talented life lost much too soon, many celebrities expressed their condolences on their Twitter platforms, reaching millions of followers who share in the grief.

Below are some of their electronic sentiments:

• Ellen DeGeneres: "My heart breaks for the friends and family of Cory Monteith. What a loss."

• Kim Kardashian: "Just heard about the death of Cory Monteith. So sad. Prayers 4 his family. Praying 4 Lea too! Words can't describe what they must be feeling."

• Katy Perry: "Rest in peace Cory. My heart goes out to his family and loved ones. Our prayers are with you."

• John Stamos: "We talked about how lucky he felt to be alive-and sober. We talked about playing drums. Glad i knew you Cory."

• Neil Patrick Harris: "How sad to read about Cory Monteith passing away. What a shame. He was a lovely, kind, talented guy and will be missed."
 

For more information on this story, click here.