A gunman killed more than 50 people and wounded at least 500 others Sunday night in the deadliest mass shooting in modern U.S. history. The attack took place at an outdoor country music show in Las Vegas, Nevada. A crowd of more than 22,000 had gathered for the Route 91 Harvest Festival, not far from Las Vegas’ famous Mandalay Bay Hotel and Casino. From the hotel’s 32nd floor, police say, a gunman opened fire on the people below.