An outdoor country music festival ended in tragedy in Las Vegas as more than 50 people have been pronounced dead in what is considered the worst mass shooting in modern American history.

It took one gunman, who police identified, shot, and killed as Stephen Paddock, 64, to open fire from the 32nd floor of the Mandalay Bay Resort and Casino,l to cause havoc in Las Vegas Sunday night, according to NBC.

The tragedy also left more than 200 people hurt.

It took place as country star Jason Aldean was performing, according to a statement from Sheriff Joseph Lombardo.

Police received reports around 10 p.m., 1 a.m. ET, of a shooting. They discovered weapons in his hotel room. They had to use explosives to enter the room. Police later found a woman, Marilou Danley, 62, who has been described as the shooter’s roommate. They have said she is not a person-of-interest in the tragedy.

Off-duty officers are included in the death toll and injured.

Concertgoers gave their accounts of how the events unfolded.

“We heard what sounded like firecrackers going off. Then all of a sudden we heard what sounded like a machine gun. People started screaming that they were hit… When we started running out there were probably a couple hundred [people] on the ground,” Meghan Kearney told MSNBC.

Jake Owen, who also was a performer for the night, revealed he was just 50 feet away from Aldean when gunfire resounded.

“It got faster and faster, almost like it was an automatic rifle,” he said. “At that point, everyone on stage started running everywhere. It wasn’t something that was quick. It was chaos for a pure seven to ten minutes.”

Aldean took to Instagram to speak on the shooting that evening.

“Tonight has been beyond horrific,” he wrote. “I don’t know what to say but wanted to let everyone know that Me and my Crew are safe. My thoughts and prayers go out to everyone involved tonight. It hurts my heart that this would happen o anyone who was just coming out to enjoy what should have been a fun night.#heartbroken #stopthehate.”

Donald and Melania Trump shared their condolences on Twitter.

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