Colin Kroll, a co-founder and CEO of popular trivia app HQ Trivia, has reportedly died from an overdose. He was 34.

The NYPD confirmed that Kroll was found in his Spring Street apartment after midnight today. TMZ reports, "Kroll's girlfriend called police early Sunday and asked them to check up on him after she was unable to get in touch. Cops went to downtown Manhattan to do a welfare check, entered his apartment and found Kroll's body in his bedroom with drug paraphernalia nearby."

"Marijuana and heroin were found nearby, and he was declared dead at the scene, the source said. Cops said an envelope containing white powder was also recovered," according to the Post.

The medical examiner's office will determine cause of death.

Kroll and Rus Yusupov co-founded HQ Trivia, which allows players to tune in for a live, 15-minute trivia show with cash prizes. The app, dubbed a "millennial Jeopardy," raised $15 million at a $100 million valuation. However, Recode had reported that when Kroll was at Twitter—Kroll created Vine, the 6-second video sharing app, which was acquired by Twitter in 2012—he allegedly "exhibited creepy behavior toward female colleagues." Twitter fired 18 months after the acquisition.

In a statement released in March, Kroll said, "As reported in the media, I was let go from Vine four years ago for poor management. It was a painful experience, but an eye-opening one that served as a catalyst for professional development and greater awareness in the office. I now realize that there are things I said and did that made some feel unappreciated or uncomfortable. I apologize to those people. Today, I'm committed to building HQ Trivia into a culture-defining product and supporting the dedicated team that makes it all possible."

A relative of Kroll's told the Daily News, "We really honestly don’t even know all the details. I’m sure they will unfold as they may but please keep in mind that people are grieving."

Kroll had told the NY Times that HQ Trivia was based in NYC and not tech-centric San Francisco because "our inspiration is more from media and TV than it is from technology."