Carl's mom, Janet, tells us the social media star was killed Tuesday in Pennsylvania. Janet says Carl was driving with a close friend -- he was in the passenger's seat -- when they were struck by another vehicle in the middle of an intersection.

Carl grew his TikTok following to nearly 500,000 before his death. We're told his family is planning two memorial services, and may live stream the events so his fans can participate.

As for what will happen with his TikTok account, that's still up in the air ... Janet says they don't yet know if his family will take it over, or if there's any material to still be posted.

Carl's page was full of videos, mostly of himself, where he'd combine humor and wit to show his fans a day in the life as he navigated the world.

Carl was only 35.