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Jason Aldean and pregnant wife Brittany have reported themselves safe after a mass deadly shooting in Las Vegas on Monday morning (Oct. 2).

"Tonight has been beyond horrific. I still don't know what to say but wanted to let everyone know that Me and my Crew are safe," Aldean writes on Instagram.

More than 50 people were killed and many more injured when a single gunman, later identified as 64-year-old Stephen Paddock, opened fire on a crowd gathered at Route 91 Festival, which was closing out Sunday night (Oct. 1). Aldean was performing his headlining set when the incident occurred. Fan video shows rushing offstage mid-song as the shooting began.

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"My thoughts and prayers go out to everyone involved tonight. It hurts my heart that this would happen to anyone who was just coming out to enjoy what should have been a fun night," he continues.

He had been singing "When She Says Baby" when a series of popping sounds began. Once Aldean realized what was happening, he raced offstage. Warning: the following video shows the moments shooting began and may be considered graphic.

Wife Brittany Aldean (Williams) was with him at the three-day festival, which ran Sept. 29-Oct. 1. She is pregnant — the couple is expecting a baby boy in December. "We are safe ... our angels were definitely watching over us tonight," she says. "No words for what happened ... Just horrific. Praying for everyone."

According to reports, off-duty police officers are among the dead. Police believe there was a single gunman, who is dead. It is reported that the gunman had a "significant advantage" over the crowd, firing from a hotel room.

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