Colin Kroll, the founder of Vine and HQ Trivia, has died aged 35.
The New York Police Department said officers went to Kroll's apartment in Manhattan early on Sunday after getting a call asking for a wellness check on him.
They found him unconscious and unresponsive on his bed.
He was pronounced dead at the scene.
The medical examiner's office will determine the cause of death.
Kroll founded the video hosting service with Dom Hofmann and Rus Yusupov in 2012 and it was acquired by Twitter later that year.
The service allowed users to upload six-second-long looped videos, and was discontinued in 2016.
Kroll also co-founded HQ Trivia and was named CEO of the company in 2015.
The trivia game goes live twice a day and asks players increasingly difficult questions as they attempt to win prize money.
He also worked for a period at Twitter.
