A heavily armed 64-year-old man named Stephen Paddock broke out a window on the 32nd floor of the Mandalay Bay Resort and Casino in Las Vegas late Sunday evening and opened fire on the Route 91 Harvest Music Festival, attended by roughly 22,000. Paddock murdered 59 people and injured around 500 in what has become the deadliest mass shooting in modern American history.

Unsettling videos taken by concertgoers reveal a scene of chaos and horror, with thousands of individuals attempting to find cover in the face of intermittent automatic machine gun fire. Many of them were injured in the ensuing stampede. The tragedy was compounded by the gunman’s position, which gave him a near unparalleled view of the concert venue below. Paddock committed suicide before authorities could apprehend him.

Currently, Paddock’s motive is unknown, but there is no evidence to suggest international terrorism was involved. Before the shooting, Paddock appeared by all accounts to be a decidedly normal person, with no criminal record (although his father had a substantial one) and no apparent reason to commit such an atrocious crime. Shortly before the shooting, he had made sizeable gambling transactions.

President Trump referred to the shooting as “an act of pure evil” and will be visiting Las Vegas on Wednesday. He did not, however, answer questions posed by reporters concerning gun control. Although the incident will likely renew, and to some extent already has renewed, the ongoing debate concerning this issue in the United States, the nation is united in mourning those who lost their lives in the tragedy.