At least 58 people were killed and hundreds more were injured when a gunman opened fire on a music festival crowd from the 32nd floor of the Mandalay Bay Resort and Casino, Las Vegas, Oct. 1, 2017. The attack is the deadliest mass shooting in modern U.S. history.

Pictured: People scramble for shelter at the Route 91 Harvest country music festival, Oct. 1, 2017, in Las Vegas.
David Becker/Getty Images