Keenan Cahill, YouTube Star, Dead at 27

The popular internet sensation died Thursday.

YouTube star Keenan Cahill, who first became popular for his celebrity lip-sync videos in 2010, has died, according to multiple reports. He was 27.

Cahill had undergone open heart surgery on Dec. 15, his manager told TMZ, but there were complications to the procedure, leading to the internet personality being put on life support. Cahill died Thursday in a Chicago-area hospital after being taken off life support. ET has reached out for confirmation.

The beloved YouTube sensation gained notoriety on the video platform more than a decade ago when he became one of the first channels to garner over 500 million views. His channel has more than 721,000 subscribers.

His most popular lip-sync video, which has 60 million views and was uploaded November 2010, features 50 Cent and sees the duo covering the rapper's song with Jeremih, "Down on Me."

The second most popular video on Cahill's channel is a lip-sync of Katy Perry's "Teenage Dream," which has over 58 million views since it was posted August 2010.

Other celebrities appeared on his channel during the height of his popularity, including David Guetta, Jersey Shore's DJ Pauly D, Ariana Grande, Jason Derulo, the Glee cast, LMFAO and Nick Cannon.

He also performed with LMFAO at the American Music Awards in November 2011 and made an appearance in a director's cut of Sara Bareilles' "Uncharted" music video that same year.

Just three weeks ago, Cahill shared his latest project, an original song featuring artist Jillian Jensen, called "Rain."

Cahill's last post on Instagram was on Dec. 12, when he shared the date of his open heart surgery to his nearly 20,000 followers.

He was diagnosed with a rare genetic disorder, Maroteaux–Lamy syndrome, as a baby. According to MedlinePlus, an online medical resource, it is a progressive condition that causes tissues and organs to enlarge, become inflamed or scarred and eventually atrophy, and it can also lead to heart problems.

Rest in peace.

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