More than 50 people were killed and over 200 injured when gunman opened fire on people attending a country music festival in Las Vegas, police said.

The mass shooting is now the worst in U.S. history since forty-nine people were killed in a shooting at the Pulse nightclub in Orlando, June 2016.

All over social media, people expressed grief, confusion and dismay that such an tragedy could have happened, including Orlando's mayor.

President Donald Trump was briefed on the situation, offering his sympathies to the victims and families in tweet this morning.

Here in Tennessee, the country music world was shaken. Some Nashville stars were in Las Vegas for the Route 91 Harvest festival near the Mandalay Bay Casino, including Murfreesboro native Chris Young. He tweeted "I love you guys" as sat helplessly amid the sounds of gunfire.

Knoxville singer Chris Blue asked for prayers for those involved in the shooting.

Knoxville native and country pop singer Kelsea Ballerini offered her support to the victims and Jason Aldean. Aldean was performing on stage in Las Vegas as shots rang out and is reportedly safe.

Tennessee lawmakers, local leaders and other authorities went to social media to ask for peoples' support for the families, victims and law enforcement responding to the deadly shooting.