NASHVILLE — Brittany Aldean's mind turned to her unborn baby as a gunman opened fire on thousands of people Sunday night while her husband, country star Jason Aldean, performed at the Route 91 Harvest Festival in Las Vegas.

“As we laid behind equipment onstage with some of our road family, bullets flying past … all I could think was, ‘I never even got to hold my baby,’ ” she wrote in an Instagram post Wednesday afternoon.

She wrote that she and her friends were in a tent near the Mandalay Bay Resort and Casino when 64-year-old Stephen Paddock started shooting from the 32nd floor of the building.

Baby Shower debauchery🎉📸👶🏼

A post shared by Brittany Aldean (@brittanyaldean) on

She also wrote her first instinct was to run to her husband.

"I can't put into words the pain and heartache we feel for the ones who are no longer with us. May God be with their friends and families during this horrendous time. Each and everyone one of you are and will forever be in our prayers."

The shooting, the worst in modern U.S. history, left 59 people dead and more than 500 injured. Police say the gunman took his own life.

Took me a while to be able to write these words... thank you to everyone who has reached out to Jason and I... Means the world to us💙

A post shared by Brittany Aldean (@brittanyaldean) on