Law enforcement sources tell us a passerby called 911 Thursday after discovering Cooper unconscious in a mall parking lot outside Los Angeles. We're told paramedics arrived on scene shortly thereafter, but were unable to revive the young social media star.

Our sources say Cooper was not in a vehicle, and there were no signs of trauma on his body. At this time, we're told there's no foul play suspected and an autopsy will be performed.

Just hours before Cooper died, he posted an image of himself in bed on TikTok with the caption, "who else b thinking they gon d!€ young af."