(CNN) At least 58 people were killed and more than 500 were hurt Sunday night when Stephen Paddock rained gunfire on concertgoers in Las Vegas, the deadliest mass shooting in modern US history .

How the attack unfolded:

• At about 10:08 p.m. Sunday, the Route 91 Harvest festival, an outdoor country music concert, was interrupted by the sound of gunfire, witnesses said.

Singer: It was like shooting fish in a barrel

Singer: It was like shooting fish in a barrel 01:48

Singer: It was like shooting fish in a barrel

• Police said the gunman fired on the crowd of about 22,000 people from the 32nd floor of the Mandalay Bay Resort and Casino, several hundred feet southwest of the concert grounds.

• Country music singer Jason Aldean was performing when the gunshots began, according to witnesses' cell phone video.

• "The gunshots lasted for 10 to 15 minutes. It didn't stop," said witness Rachel de Kerf.

• Police say Paddock fired for nine to 11 minutes after the first 911 call came in.

• Paddock set up cameras inside his hotel suite and in the hallway. Police are not aware whether the devices were transmitting.

Investigation:

JUST WATCHED Jason Aldean runs off stage as shooting erupts Replay More Videos ... MUST WATCH Jason Aldean runs off stage as shooting erupts 01:03

• Authorities identified the shooter as 64-year-old Stephen Paddock of Mesquite, Nevada, a retired and twice-divorced accountant with no known children.

• Paddock was alive when officers first made contact with him outside suite 32135. After taking gunfire from him, police backed off and waited for SWAT teams to respond. A security guard was shot in the leg.

• Officers "breached the hotel room" where Paddock was and found him dead, police said. Authorities believe he killed himself.

• Police said they believe Paddock acted alone.

• Police say they have not determined Paddock's motives. As such, they are not calling the shooting terrorism -- an attack on civilians to intimidate or coerce society for political purposes. "We have to establish what his motivation was first," said Clark County Sheriff Joseph Lombardo, when asked why the shooting has not been labeled domestic terrorism.

• The FBI says it has determined no connection with an international terrorist group.

• "We had no knowledge of this individual," Lombardo said of Paddock. "I don't know how it could have been prevented."

• Twenty-three weapons were found in the hotel room, including multiple rifles, and some had scopes on them, authorities said.

• Lombardo says several pounds of ammonium nitrate, a material used to make explosives, were found in Paddock's car.

• Authorities searched Paddock's home in Mesquite and found at least 19 more firearms, as well as explosives, several thousand rounds of ammunition, and some electronic devices.

• The shooter had bought multiple firearms, several in California, a law enforcement official told CNN.

• So far, investigators believe the firearms were purchased legally. The suspicion, based on initial reports, is that at least one of the rifles used was altered in order to function as an automatic weapon, said the official.

• The shooter had been at the Mandalay Bay hotel since September 28, authorities said. Hotel employees had been in his room prior to the shooting and did not notice anything amiss, according to Lombardo.

• Paddock wired $100,000 to the Philippines, but officials don't know precisely when the transfer happened or whom the recipient was, a law enforcement official said Tuesday. The FBI is working with Filipino authorities to determine details, the official said.

Paddock's background:

• Besides being a retired accountant, Paddock was a real estate investor who owned apartments and houses. Investigators were looking at several properties in the Reno area associated with him.

• Paddock graduated from California State University, Northridge in 1977, with a degree in business administration.

• After living for a time in Melbourne, Florida, Paddock moved to Nevada in 2016 , his brother, Eric Paddock, said.

• Stephen Paddock lived in Mesquite, Nevada, with his girlfriend, Marilou Danley, police said. She was out of the country during the shooting, and is not believed to have been involved, police said.

• Eric Paddock told CNN about Stephen: "He was my brother and it's like an asteroid fell out of the sky." He said the last time he spoke to his brother was when Stephen texted, asking how their mother was after she lost power when Hurricane Irma hit Florida.

• Eric Paddock said his brother had never shown violent tendencies, and had no affiliations with any terror or hate group. Paddock says he's still in the dark on why his brother would do this.

• Stephen Paddock's father was a convicted bank robber who was on the FBI's most wanted list , from June 10, 1969, until May 5, 1977, the FBI said. Eric Paddock said his father, who was arrested in Oregon in 1978, died a few years ago.

Casualties:

• At least 58 dead and more than 500 people taken to area hospitals, authorities said.

• Throngs of blood donors lined up outside Las Vegas blood banks all day Monday. US blood banks currently have enough blood to meet the immediate medical needs of patients being treated in the aftermath of the shooting, according to a blood bank official.

• This is the deadliest shooting in modern US history. The 2016 Pulse nightclub shooting in Orlando, Florida, previously was the deadliest, with 49 killed.

• a nurse, a police records technician, a special education teacher, and a school office manager. Victims include a nurse, a police records technician, a special education teacher, and a school office manager.

Reaction:

• Nevada Gov. Brian Sandoval signed a declaration of Emergency for Clark County, which allows state agencies to supplement local efforts.

• The Department of Homeland Security said there is no credible threat involving other public venues, but security could increase.

• President Donald Trump described the shooting as an "act of pure evil" and said he will visit Las Vegas on Wednesday to meet with families of the victims.

• Trump and first lady Melania Trump led a moment of silence for Las Vegas from the White House on Monday.

• The Orlando Police Department, which investigated the 2016 Pulse nightclub shooting, tweeted its condolences to those affected by the Las Vegas shooting.

This article has been updated to reflect a change in the victim death toll.