This Thursday, July 20th, millions of fans and friends around the world were devastated to discover that Chester Bennington, frontman of alt-rock band Linkin Park, had died by suicide.

Bennington, 41, had spoken openly about his struggles with depression and substance abuse before. “I literally hated life," he told Rock Sound in 2015 , “and I was like, ‘I don’t want to have feelings. I want to be a sociopath. I don’t want to do anything. I don’t want to care what other people feel like. I want to feel nothing.'"

He talked about having been a victim of ongoing sexual abuse as a child, for which he had never sought help until after it had ended due to threats from the perpetrator, and explained that several of his songs’ lyrics alluded to feeling overwhelmed by hopelessness, drugs, alcohol, and suicidal ideation. “That’s where the line, ‘If I just let go, I’d be set free’ comes from — that’s what ‘Heavy’ is about. When I’m opening that song saying, ‘I don’t like my mind right now’, that’s f—ing real. It is not a safe place for me to be unless I’m doing what I need to do: taking care of myself, being real, being open, getting it out, taking all the steps to make myself whole. Then it’s a pretty safe neighborhood, but it goes bad real fast. It’s great to get that s— out," he said in 2017.

Mental illness plays a role in over 90 percent of suicides worldwide, but Bennington’s reveals an often-overlooked factor that may contribute to someone’s decision to take their own life: July 20, 2017 would have been the 53rd birthday of his close friend, Soundgarden frontman Chris Cornell, who also died by suicide this May.

Bennington’s death seemed to mirror Cornell’s. Both hung themselves, Cornell with an exercise band on the door separating a hotel bedroom from the bathroom and Bennington with a belt on the closet door in a bedroom. Neither left a note. Cornell was reportedly under the influence of medications, and a partially empty bottle of alcohol was found in the room where Bennington died.

Experts say it makes sense that Bennington’s suicide took place on the birthday of a friend who died so recently. Important occasions such as birthdays, anniversaries, and holidays can be extremely emotionally taxing for those who have lost a loved one and can increase not only their level of distress but also their risk of depression, self-harm, or suicide. It is likely that his heightened vulnerability on the birthday of his lost friend exacerbated Bennington’s preexisting depression and sorrow.

"Anniversaries bring up the fact that the person isn't with us anymore," said the president of the American Association of Suicidology, Julie Cerel. "It becomes a time of risk for people who are hopeless and hurting." Cerel suggests planning in advance of a fallen loved one’s birthday or other important event. For example, scheduling a vacation to spend the day out of town can help alleviate the emotions and make the day more manageable.

Bennington and Cornell met in 2007 and became close when they toured together in the late 2000s, and Bennington sang Leonard Cohen’s “Hallelujah" at Cornell’s memorial service. He penned a heartfelt open letter to his friend and shared it on Twitter after the news of his passing:

Cornell’s wasn’t the only death weighing on Bennington’s mind. In 2015, another close friend since 2001 and inspiration since his childhood, Scott Weiland of Stone Temple Pilots, died unexpectedly “in his sleep." Weiland and Bennington shared several similarities: both had been sexually abused in youth, found quick and astounding success in their bands, struggled with depression and addiction, and were frontmen for STP. Bennington called it a lifelong dream to be a member of STP and did not take the opportunity lightly once he had it; he gave it his all and brought his own personality to the songs for two years until he left to resume work with Linkin Park and spend time with his six children.

Weiland, Cornell, and Bennington were connected personally and artistically, emerging as powerhouses of their genre and uniting generations of listeners who identified with their pain.

Friends, fans, and fellow musicians took to social media to express their heartbreak over Bennington’s death and to thank him for his contributions to their lives and to the world of music:

• “Artists are ppl compelled to bring beauty into a world that can be so dark. makes sense then that artists are always conscious of darkness.. ... & maybe at times made more vulnerable by it? i don't know. life can be relentless. heart hurts for Chester's family/band/friends/fans." – Hayley Williams of Paramore

• “RIP. Mental health is not a joke. Heartbreaking " -- Best Coast

• “Oh dear God. Massive R.I.P to Chester Bennington of @linkinpark this BREAKS OUR HEART. Suicide is the devil on earth walking amongst us " -- One Republic

• “I am in tears. Chester just told me how happy he was…..He was such a sweet and talented man……I feel so sad for his family, band mates and fans" – Nikki Sixx of Motley Crue

• “Just when I thought my heart couldn’t break any more..." – Chris Cornell’s wife Vicky

If you or someone you know is considering self-harm or suicidal thoughts, please get help. Call 9-1-1 or the National Suicide Prevention Lifeline at 1-800-273-8255, text the Crisis Text Line at 741- use the Online Suicide Prevention Chat at crisischat.org/chat , or visit the Online Crisis Network at imalive.org.