Jewel reportedly cautioned longtime friend and former Zappos CEO Tony Hsieh about his lifestyle shortly before his untimely death.
According to an article published by Forbes on Friday, the 46-year-old singer wrote a letter to Hsieh that warned him about "taking too many drugs" after she had performed for him in August at a private acoustic set in Park City, Utah.
The publication reported that Hsieh was planning to show the songstress around the mountain town in the days following her performance, but she left abruptly Park City. The singer then sent the businessman a letter through FedEx shortly after her departure as he no longer could get emails as he had decided to do a digital purge, Forbes reports.
"I am going to be blunt," she wrote in the letter, obtained by Forbes. "I need to tell you that I don’t think you are well and in your right mind. I think you are taking too many drugs that cause you to disassociate."
Jewel reportedly told Hsieh in the note that "people you are surrounding yourself with are either ignorant or willing to be complicit in you killing yourself."
“When you look around and realize that every single person around you is on your payroll, then you are in trouble," Jewel wrote, according to Forbes. “You are in trouble, Tony.”
A representative for Jewel did not immediately respond to PEOPLE's request for comment.
Hsieh died on Nov. 27 at the age of 46 after sustaining injuries in a Nov. 18 Connecticut house fire, PEOPLE previously reported. A statement provided to PEOPLE from DTP Companies, which Hsieh founded, said he died surrounded by family.
"Tony’s kindness and generosity touched the lives of everyone around him, and forever brightened the world," the statement read. "Delivering happiness was always his mantra, so instead of mourning his transition, we ask you to join us in celebrating his life."
Connecticut Office of the Chief Medical Examiner later confirmed to PEOPLE that Hsieh died from complications of smoke inhalation and his death was ruled as an accident.
Jewel paid tribute to Hsieh on Wednesday in a tearful YouTube video titled "Elegy for Tony Hsieh."
"I lost my dear friend Tony Hsieh. He founded Zappos, Life is Beautiful music festival and the Downtown Project in Vegas," she wrote in its description. "I have been at a loss for words, and unable to post adequately, because an entire life summed up in a meme is ... well... impossible."
"This is my elegy, Tony. This is me singing for you. May it find you smiling on the other side of the rainbow," Jewel continued. "I have never managed to sing while I cry. But here the tears flowed ... if anyone has lost a loved one recently, this is for you, too. May we all heal together from the losses of the year."
In the 11-minute clip, which featured an acoustic performance of "Somewhere Over the Rainbow," the folk music star spoke about meeting Hsieh on Richard Branson's Necker Island and how she was "riveted" by his spirit.
"Tony was very fearless," Jewel said. "I remember he asked me what my definition of success. I can't remember what my answer was, but I remember his. His answer was: the willingness to lose it all, believing in an idea so much that you're just willing to be wrong."
"That really is a beautiful definition, and that really is how I think of Tony — very brave," she added.
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