A gunman armed with at least 23 firearms unleashed a hailstorm of bullets on a country music festival in Las Vegas, killing at least 59 and wounding a further 527.
Here's how America's worst mass shooting unfolded.
On September 29, Stephen Paddock checks in to a room on the 32nd floor of the Mandalay Bay Resort and Casino on the world-famous Las Vegas strip.
He brings in a cache of high-powered rifes, including some equipped with scopes. It is believed he used the identification of a companion, Australian citizen Marilou Danley, to book the room.
At 9.40pm (local time) on October 2, musician Jason Aldean takes the stage as the last act of the three-day Route 91 Harvest Country Music Festival across from Mandalay Bay.
Around 20 minutes later, Paddock uses a hammer-like device to smash through two windows of the high-rise casino and then begins to fire into the crowd of 22,000 concertgoers below.
Aldean, midway through one of his final songs, realises what is happening and rushes off stage. Concertgoers scream and attempt to flee as shots rain down from above. Victims start falling in a scene of total chaos.
The first call over police radio is heard at 10.08pm. An officer reports that shots have been fired and that it sounds like they are coming from an automatic weapon.
As the police dispatch responds confirming a "code red", the officer cuts in: "It's coming from upstairs in the Mandalay Bay. Upstairs Mandalay Bay, halfway up. I see the shots coming from Mandalay Bay, halfway up."
Country music star Jake Owen, who was on stage with Aldean, later tells CNN it was like "shooting fish in a barrel from where he was".
Witness Michelle Leonard recalls to ABC news that "it sounded like a thousand shots".
At 10.38pm, police tweet that they are investigating reports of an active shooter near Mandalay Bay and ask people to avoid the area.
At 11pm, police say that parts of the famous Strip have been closed down. Flights are diverted from Las Vegas Airport within the next half an hour.
Just before midnight, heavily armed SWAT police storm the 32nd floor and find Paddock in a pool of his own blood. They find at least 23 firearms in his room. Around 12.30am, police tweet that they aren't looking for any more shooters.
At 1.30am, Clark County Sheriff Joseph Lombardo gives his first media briefing, saying that at least 20 people are dead and more than 100 are injured.
He also states that police are looking for the gunman's "companion" Marilou Danley and a maroon Hyundai.
About two hours later, the death toll rises considerably to at least 50. Police also say that more than 200 people have been injured in the brutal massacre. The shooter is identified as 64-year-old Stephen Paddock.
Danley has been located, police say, however she is out of the country at the time.
Just before 6am, police give a new briefing to say that the number of injuries has risen to 400.
Police also say that Paddock had very little criminal history and that he was a white male from Mesquite, Nevada. They also confirm that Paddock killed himself before he encountered police.
At 7.50am, President Donald Trump addresses the nation, calling the massacre "an act of pure evil".
Not long after 8.30am, police give yet another briefing to say that 58 people have died and more than 500 people are injured, confirming it as the worst mass shooting in US history.