In what is being referred to as the worst mass shooting in modern American history, a lone gunman released a barrage of bullets from a Las Vegas hotel room Sunday night, killing at least 50 people and injuring more than 400 others.

The shooter, identified by authorities as Stephen Craig Paddock, 64, fired rounds of rapid shots from the 32nd floor of the Mandalay Bay Resort and Casino into a crowd of about 22,000, MSNBC reports.

At the time of the shooting, the crowd was attending an outdoor country music festival.

“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,” witness Meghan Kearney told MSNBC. “When we started running out, there were probably a couple hundred [people] on the ground. “People kept dropping and dropping … People were getting shot one foot away from us. People were trying to save their friends. There were gunshots everywhere.”

At least 10 weapons were found inside Paddock’s room at the popular resort and casino, officials say.

Just after 10 p.m. PST last night, police responded to reports of shooting, and authorities believe Paddock killed himself shortly before police entered his room, Las Vegas Metropolitan Police Sheriff Joseph Lombardo said Monday.

He reportedly checked into the Mandalay Bay Resort and Casino on Sept. 28, and had an “excess of 10 rifles,” Lombardo said.

Our prayers go out to those affected by this tragic act of domestic terrorism.

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