Carrie Underwood, Keith Urban and Luke Bryan are among the country singers who turned to social media to express their shock and grief and share prayers and well wishes after the deadly shootings at the Route 91 Harvest Festival in Las Vegas on Sunday night (Oct. 1).

“Woke up to such horrible news. We are praying for the victims and their families. May the Lord bring some comfort to them," Underwood writes on Twitter.

Urban says that he is "Stilled and speechless ... Our hearts and prayers are with everyone involved and affected."

“Words can’t begin explain my sadness. My family and I are praying for the victims of this tragedy,” Bryan tweeted, adding that he is "Truly heartbroken."

Photos From Route 91 Harvest Festival Show Humanity in the Chaos

The mass shooting took place Sunday night during Jason Aldean's headlining set during the last night of the festival. Aldean was onstage and had to run for cover with his band and crew as the bullets began to fly, while Jake Owen — who performed before Aldean — recounted the shooting from side stage and Chris Young was forced to take cover in a trailer.

Authorities have confirmed 58 fatalities so far, with more than 500 injured. The shooter, 64-year-old Stephen Paddock, apparently took his own life after shooting from his hotel room down on the 22,000 festival attendees for nearly five minutes. It is the deadliest mass shooting in U.S. history.

The 2017 Route 91 Harvest Music Festival marked the festival's fourth year. Sam Hunt and Eric Church headlined Friday and Saturday nights.

Checking in With All Route 91 Harvest Fest Sunday Performers