The Sunday night mass shooting in Las Vegas is officially the deadliest in U.S. history.
At least 50 were killed and 400 injured when a gunman opened fire on the audience at a country music festival from the 32nd floor of a nearby hotel. The suspected gunman, who was found dead, was identified as 64-year-old Stephen Paddock.
A former Las Vegas police officer told CBS News that the length and scope of the shooting were planned "immaculately" and made it difficult to get first responders to the scene of the attack.
Before Las Vegas, the deadliest mass shooting had been the terrorist attack at Pulse nightclub in Orlando, Fla., where 49 people were killed in June 2016.
Prior to Orlando, the 2007 Virginia Tech mass shooting was the deadliest in the country. A student at the university killed 32 people before killing himself.
The Sandy Hook Elementary School mass shooting in Newtown, Conn., where a gunman fatally shot 20 children and six adults, is now the fourth-deadliest mass shooting.
The death toll also makes the Las Vegas shooting the third-deadliest in the world.
The deadliest took place in Norway in 2011, when a right-wing extremist set off a bomb in Oslo and then went on a shooting rampage at a summer camp run by Norway's Labour Party. A total of 77 people were killed in the attack.
This report was updated at 10:27 a.m.