Gomez and Grimmie went on to perform and tour together.
Teefey has set up a GoFundMe page which he hopes will raise funds to help Grimmie's family in their time of need.
"As family mother, father, and brother made the ultimate family sacrifice to support Christina on her musical journey," he wrote on the GoFundMe page.
Christina Grimmie. Photo / AP
"They did nothing but love her and support her as family the best they knew how, the only worry I want them to have at this point is that of recovery."
He also added some words to express his own grief, saying "Words cannot begin to describe the pain I am feeling".
Christina Grimmie performing at Center Stage Theater, Atlanta. Photo / AP
"I learned this business through the eyes of a father and Christina was like a second daughter to me. All I wanted to do was assist her in achieving her musical dreams while protecting her from the pitfalls associated with the business," Brian Teefey wrote.
"I never could have imagined this horrific event being one of the pitfalls needing to be avoided...Grimms I love you, and miss you beyond comprehension."
The page has been live for about 17 hours, and has already raised more than US $40,000.
