Police found Kroll unresponsive in his Manhattan apartment after a woman he was with called 911, and confirmed that a drug overdose is the suspected cause of death. An investigation is currently underway.
Kroll co-founded Vine in 2012. The popular six-second video platform was acquired by Twitter, but was shut down in 2016. Kroll was reportedly fired by Twitter for "poor management behaviour" and inappropriate behaviour toward women.
He went on to co-found the trivia game HQ. The app launched in 2017 and became wildly popular, racking up a high of 2 million concurrent players, but the number of users drastically dropped to just hundreds of thousands last month.
According to Time, Kroll was facing allegations of inappropriate workplace behaviour at HQ, as well.
Below, read tributes from Kroll's former colleagues and companies.
So sad to hear about the passing of my friend and co-founder Colin Kroll. My thoughts & prayers go out to his loved ones. I will forever remember him for his kind soul and big heart. He made the world and internet a better place. Rest in peace, brother.
— Rus (@rus) December 16, 2018
We learned today of the passing of our friend and founder, Colin Kroll, and it's with deep sadness that we say goodbye. Our thoughts go out to his family, friends and loved ones during this incredibly difficult time.
— HQ Trivia (@hqtrivia) December 16, 2018
Colin Kroll was a true visionary who changed the app game twice, and with HQ he changed my life. He poured his heart and soul into his work and was incredibly proud of what his team accomplished. I will forever be grateful for his friendship, his leadership, and his belief in me.
— Scott Rogowsky (@ScottRogowsky) December 17, 2018