On Sunday, Colin Kroll, the CEO of HQ trivia and founder of Vine was found dead in his New York apartment. This was apparently due to a drug overdose as New York police found cocaine and heroin in his apartment.

“I will forever remember him for his kind soul and big heart,” said Kroll’s business partner Rus Yusupov in a tweet on Sunday. “Rest in peace, brother.”

Both HQ and Vine exploded in popularity after their initial releases. Vine, especially, was extremely popular until Twitter, which later bought it, shut it down in 2016.