"Very Sad," Cheryl wrote. "My heart goes out to everyone he left behind. Addiction is very hard to kick." Kim added: "Not only do I love Alice in Chains, but I watched Mike on 'Celebrity Rehab' and 'Sober House' and you get to where you feel like you know them. This breaks my heart in two...there are not words. RIP, Mike."
Other commenters echoed those thoughts, lamenting Starr's fatal addictions.
"Such a sad story about him," Kandi wrote. "I guess it's not a shock because I was watching him on 'Celebrity Rehab' & 'Sober House.' Drugs are no joke at all. RIP Mike Starr."
"Very sad to hear. My thoughts are with his family," said fellow "Celebrity Rehab" viewer Michiangel. "I watched him struggle on 'Celebrity Rehab' and really hoped that he would surpass his addiction."
Teegee16 hoped other addicts would take Starr's death to heart: "They say you can't scare an addict but here's proof again that we can most certainly die from drugs. Hopefully he didn't die in vain and someone out there got the message about how serious addiction is."
"I am so heartbroken, I don't have words," Sometimes_Charlotte wrote. "My heart goes out to his family. He meant a lot to me; I have personal reasons for this. I can only imagine how devastated his family is."
Other fans remembered Starr's musical legacy as bassist for Alice in Chains from their inception in the late '80s until 1993.
"Rest in peace brother," Thorum wrote. "Thanks for the music and good times!!"
"You made a difference in my life, however humble that might be," James A. Brennan wrote to Starr. "Rest in peace dude."
Kevin called out his favorite album by the band: "Alice in Chains, Dirt...no substitute. God bless."
This isn't the first loss for Alice in Chains fans: Frontman Layne Staley died of a drug overdose back in 2002.
"Another great loss to the band and great bassists; too young brother," Joe wrote.