One of the deadliest mass shootings in American History occurred on Sunday night in Las Vegas, NV. A gunman rained a rapid-fire barrage on an outdoor concert festival from a high floor of a Las Vegas hotel. He killed at least 58 people, injured hundreds of others, and sent thousands of terrified survivors fleeing for cover.

A three-day country music event, called the Route 91 Harvest Festival, was horrifically interrupted by the sound of gunfire near the Mandalay Bay Resort and Casino. Singer Jason Aldean’s performance was abruptly interrupted as victims fell bleeding, concertgoers screamed, ducked for cover, or ran for their lives.

At first many people in the crowd thought that the sounds came from fireworks. When they realized the sounds were that of gunshots people started running out of the venue, they thought they might be trampled, so they decided to join the rush to leave.

On Monday morning 58 people were confirmed dead and 515 more had been injured, stated Sheriff Joseph Lombardo of the Las Vegas Metropolitan Police Department. There were about 22,000 people at the concert and one of those killed was an off-duty Las Vegas police officer. Investigators saw no immediate evidence connecting the attack to an international terrorist organization said the F.B.I. special agent in charge in Las Vegas, Aaron Rouse.

The upper floors of the Mandalay Bay were swarmed with SWAT units as they closed in on the source of the shooting. The gunman was discovered in a room on the 32nd floor where they found him with “in excess of 10 rifles. We believe the individual killed himself prior to our entry,” the sheriff said.

At 10:08 p.m. local time the first reports of the shooting came through. Police radio channels were going off with reports that officers were pinned down by gunfire. The Las Vegas police reported that “one suspect is down,” shortly before midnight. Soon after, the police reported that they did not believe there were any more active gunmen. The suspected gunman was identified by the sheriff as Stephen Paddock, 64, of Mesquite, Nev., who had no significant prior criminal history.

The police searched Mr. Paddock’s house in Mesquite, a town on the Nevada-Arizona border, before dawn on Monday. The police evacuated surrounding homes in case there were any explosives, and moved cautiously during their investigation. Thankfully no explosives were found. At least one firearm and ammunition were found, and no one was in the house, said The Mesquite Police Department but they gave few other details about what the search turned up.

In an interview with CBS, Eric Paddock, a brother of Stephen Paddock who lives in Orlando, Fla., made a statement to the police. He said that his brother was “not an avid gun guy at all,” adding, “if he had have killed my kids, I couldn’t be more dumbfounded.”

Eric Paddock questioned, “The fact that he had those kind of weapons is just — where the hell did he get automatic weapons? He has no military background or anything like that,” he added. “He’s a guy who lived in a house in Mesquite and drove down and gambled in Las Vegas.”

Stephen Paddock had recently texted his brother, Eric to ask how their mother was faring after Hurricane Irma. This was the last moment of contact Stephen had with his brother Eric before he brutally opened fire into a crowd of innocent people on Sunday.