Kelly Clarkson, Sia + More React to Mass Las Vegas Shooting

The world is recoiling in horror at Sunday night's (October 1) shooting at the Route 91 Harvest Festival in Las Vegas.

Jason Aldean was performing when a shooter fired multiple rounds, killing more than 50 people and injuring hundreds more, in what is being called the deadliest mass shooting in U.S. history.

Celebrities from all walks of life have taken to social media to express their sadness at what happened, including Aldean himself, who let everyone know he was okay, but that the incident "hurts my heart."

Take a look below to see what other had to say.