The man known for his lip-synch videos has passed away.

David Graham is Keenan'smanager. He was put on life support after he had a heart surgery in December. We're told that he died in a Chicago hospital on Thursday.

He was one of the first people to rack up 500 million views on his channel on the video sharing site.

50 Cent helped take Keenan's career to the next level by collaborating with him on a song.

He worked with a lot of famous people, including Britney Spears, David Guetta, Selena Gomez, Ariana Grande, and many more.

When he was a baby, he was diagnosed with a rare genetic disorder that causes organs and tissues to enlarge and become scarred. There are some people with Maroteaux-Lamy syndrome who have heart issues.

The man was 27 years old.

I am sad.