Shortly after 10 p.m. on Oct. 1, 64-year-old Stephen Paddock opened fire on the south side of the Las Vegas Strip, where the Route 91 Harvest music festival was taking place at the Las Vegas Village near the iconic Mandalay Bay casino. The shooter was firing from the 32nd floor of the Mandalay Bay hotel, giving him a distinct tactical advantage.

More than 50 people were killed by the attack, and more than 200 others were wounded. The Las Vegas Metropolitan Police confirmed that Paddock was killed and that police do not believe there were any other active shooters, despite initial reports of multiple assailants. Mass shootings in the United States are commonly perpetrated by a single individual, but early media coverage often erroneously reports multiple shooters.

Shortly after the incident, authorities diverted and halted flights at the McCarran International Airport, located only blocks from the incident. Police also closed down the southern part of the Las Vegas Strip.

At this point the shooter appears to have no ties to Islamic terrorist groups, but the Islamic State released a 55-minute video earlier this year identifying Las Vegas as a prime target. In the video, native speakers of English, French and Arabic urged grassroots militants in the United States to carry out attacks wherever they might be, thus "avenging" their fellow fighters in Syria and Iraq. It is unclear what Paddock's motive for attack was.