Nick Cannon's childhood friend was killed in the San Diego shooting on Sunday (04.30.17).
The 36-year-old presenter shared a heartbreaking story about how his close pal Monique Clark - a mother of three - lost her life along with six other victims when "senseless" gunman Peter Selis opened fire at an apartment in the Californian city.
Nick - who has five-year-old fraternal twins Moroccan and Monroe with ex-wife Mariah Carey - has been left distraught by the loss of his friend and is in "pain and shock" over the tragedy.
He insists he only has "wonderful memories" of Monique and said her "beautiful spirit" will live on.
In a tear-jerking tribute to Monique posted alongside a throwback photo of the pair when they were younger, he wrote on Instagram on Tuesday (02.05.17): "My heart hurts with great sadness tonight. I just learned that the one life lost in the senseless and tragic mass shooting in San Diego was my childhood friend, who was more like family, Miss Monique Clark. Such a beautiful spirit with an infectious smile. I have nothing but wonderful memories of this Angel. Tears can't express the pain and shock. A mother of 3, a sister, a daughter, a cousin, a friend and a Queen... Rest in Paradise. (sic)"
According to reports, the gunman, who was shot by cops, was "despondent" about his love life when he aimed the gun at the civilians.

Mariah Carey has posted a touching throwback picture of her twins Moroccan and Monroe on their sixth birthday.
The 36-year-old star took to Instagram on Sunday (30.04.17) to share with her 5.6 million followers a sweet picture of her cradling her little ones and gushed about how she loves them "more each day".
She also referenced them being born to the live track of her song 'Fantasy'.
She wrote: "I can't believe it has been six years since you two came into this world to the live version of Fantasy.. "the applause!!!" I love you both more each day. You are the light of my life #Supernatural #HappyBirthday #RocnRoe (sic)"
Meanwhile, the 'We Belong Together' hitmaker's ex-husband Nick Cannon, whom she had the twins with, is rumoured to be on the cusp of rekindling his romance with the blonde beauty - but Nick has insisted the duo are simply "family" for the time being.
Responding to the speculation, Nick recently said: "You do realise we're family, right? I meet them everyday."
Despite this, Nick recently admitted he wouldn't rule out a reunion with Mariah, although he doesn't want to "mess up what they have right now".
He said: "That is always family - and when I say that, I say that to a level of I will always love her. That's always my dream girl. Like, to me, just because we're not intimate, I'm closer with her than probably I've ever been just based off of that's my family, that's the mother of my children.
"We talk every single day. We spend more time with the kids' school, karate class, gymnastics class, like, it's a full-time job. I wouldn't want to mess up what we have right now trying to do something else."
In fact, Nick revealed he prefers to "purposefully" stay out of Mariah's personal life, following her recent split from dancer Bryan Tanaka.
He said: "I don't know because I'm not in it. I'm purposefully like, 'Let's go do something with the kids. I don't care what you do in your personal life.' I don't know. I thought it was bizarre as somebody watching from afar. I thought the show was very produced.
"I didn't say that their relationship was just for show. I thought the show fabricated a lot of stuff because, as a producer, I was like, 'Oh, they positioned that. They put the cameras there.' I was watching it from that perspective. But I don't know what the relationship actually is."