What we know:
- What happened: At least 58 people were killed and more than 515 injured in a shooting outside the Mandalay Bay Resort on the Las Vegas Strip during a music festival on Sunday night. It is the deadliest mass shooting in US history. Shots were fired from the 32nd floor of the resort, according to police. Country singer Jason Aldean was performing at the time.
- What we know about the suspect: Las Vegas Metropolitan Police Sheriff Joseph Lombardo named the suspect as 64-year-old Stephen Paddock. Described as a "local resident," the suspected shooter has been killed. Inside his room, officers found a cache of weapons, including 10 rifles. Lombardo said police have tracked down Paddock's female companion, Marilou Danley.
- What we know about the victims: Off-duty police officers are among the dead, according to LVMPD Sheriff Joe Lombardo. Their identities have not been released. Two police officers are also being treated for injuries -- one officer is in critical condition and the other has minor injuries.
[Breaking news update at 8:35 a.m. ET]
At least 406 people have been taken to hospitals following a massacre on the Las Vegas Strip overnight, police said.
At least 50 people were killed in the shooting rampage during a Jason Aldean concert. An off-duty Las Vegas police officer was among those killed, the police department said.
Authorities say the suspect, 64-year-old Stephen Paddock of Mesquite, Nevada, fired from the 32nd floor of the nearby Mandalay Bay hotel. Officers found at least eight weapons, including multiple long rifles, in Paddock's room, Las Vegas Police Undersheriff Kevin McMahill told CNN.
Paddock was eventually killed.
"He was shot, but I cannot tell you that it was the police that shot him," McMahill said. "He may have self-inflicted that gunshot wound. Those details are still emerging throughout our investigation."
[Previous story, published at 6:08 a.m. ET]
LAS VEGAS (CNN) — More than 20 people were killed and more than 100 injured in a shooting on the Las Vegas Strip on Sunday night, police said.
Las Vegas Metropolitan Police Sheriff Joseph Lombardo told reporters that police responded after reports of shots being fired from the Mandalay Bay toward the Route 91 Harvest festival around 10:08 p.m. Sunday (1:08 a.m. ET Monday).
"We determined there was a shooter on the 32nd floor of the Mandalay Bay," Lombardo said. Officers engaged the suspect, whom Lombardo described as a "local resident." He said that the shooter is dead and that police believe that there are no other shooters. "Right now, we believe it's a sole actor, a lone-wolf-type actor," said Lombardo.
Police have identified the gunman but will not be naming him at this time, Lombardo said.
Though it's too early to give an accurate estimate of the number of dead and wounded, Lombardo said that "20-plus" have died and "in excess of 100" people have been injured.
Police are searching for a woman named Marilou Danley who was traveling with the suspect, Lombardo said. He described Danley as an Asian woman, 4 ft 11 inches tall and 111 pounds. "We have not located her at this time and we are interested in talking to her," he said.
Two Las Vegas police officers are being treated at a local hospital for injuries they sustained during the shooting, Lombardo said. One is in critical condition and the other sustained minor injuries.
In addition, the sheriff stated that there were off-duty officers attending the concert who may have died. The identities of the officers involved have not been released.
"Pray for Las Vegas," the mayor tweeted. "Thank you to all our first responders out there now."
Nevada Gov. Brian Sandoval said on Twitter that a "tragic & heinous act of violence has shaken the #Nevada family" and offered prayers to all those affected by "this act of cowardice."
Concertgoers describe shooting
CNN spoke to three people who were attending the concert at the Las Vegas Village outdoor arena when gunfire broke out, causing them to flee. They described hearing the sound of gunfire while Jason Aldean was performing.
Aldean, his wife Brittany, his band and crew were able to get offstage safely and unharmed.
"We were close to the stages -- about six rows from the front on the left hand side and he was just performing," Rachel Dekerf said.
"People went down on the Mandalay side of the stage," Joe Pitzel said. "I don't know if people were ducking or if people were hit."
Derkef filmed her escape from the venue using her cell phone, starting just after the first shots were fired.
She described ongoing gunfire, and played out the video she had recorded during which more than five minutes of gunfire were intermittently audible.
"The gunshots lasted for 10-15 minutes. It didn't stop," she said. "We just ran for our lives."
'Go, go, go, go'
Derkef's sister, Monique Dumas, said that everyone instantly crouched when they heard the shots.
"The band was rushed off the stage, the floodlights came on the crowd, and you see on the right hand of the stage the person who was injured, so they're calling for medics, calling for security, then there was gunfire again," Dumas said.
"It seemed there was a pause in the gunfire and the people in the yellow shirts were telling the people to 'go, go, go, go' ... the gunfire never ended, it seemed like it went on and on and on," she said.
SiriusXM Country radio host Storme Warren was on the side of the stage as Aldean was performing and shots rang out.
"I thought it was fireworks going off and maybe it mistriggered, and then it happened again. And when it happened the third time, we knew something was wrong," Warren said. "To say that I saw things I never want to see again is the truth, and it's a scary situation."
Warren said he heard "more than 50 shots fired and probably in the hundreds."
"The shells were hitting the deck of the stage when I was on it," he said, adding that he could still hear the shells as he went under the stage for protection.
Aldean posted a statement on Instagram saying that he and his crew were safe after a horrific night.
"My Thoughts and prayers go out to everyone involved tonight. It hurts my heart that this would happen to anyone who was just coming out to enjoy what should have been a fun night. #heartbroken#stopthehate," he wrote.
A concertgoer told CNN affiliate KLAS that everybody was lying on top of each other trying to get out of the shooter's way.
"Everybody's hiding everywhere, they're hiding under the bleachers and the stanchions, anywhere they could and everyone is telling us to 'run, run as fast as you can,'" she told the news station. "And my husband and I ran out toward our car and there were people hiding underneath my car for cover and there was a gentleman who was shot and he said, 'can you help me?' and so I put him in my car and I had like six people in my car, people without shoes, running, just to get away."
'Sounded like firecrackers'
Eyewitness Bryan Heifner spoke to CNN from a room in a hotel across from the Mandalay Bay, which he said he could see from his window.
"Mostly I heard the shots, just so many shots -- I just thought it was a semi braking with the air brakes, but then I went downstairs and saw people running and looking for family," he said.
"I immediately went back to my room, locked the door, turned the lights off."
Another witness told CNN affiliate KSNV that the shooting sounded like firecrackers at first.
"It didn't sound normal, it sounded like machine guns and it was like several rounds, it was like hundreds of rounds," she told the news station.
"My boyfriend had me move behind a building here because it just didn't sound right," she told KSNV. "And then we hid behind a building and we could just hear hundreds of rounds going off and then about 10 minutes later the police came and just blocked off all the streets."
She said she was about a block from the Route 91 Harvest festival.
James Gagliano, CNN law enforcement analyst said the audio of the shooting suggested that the shooter had used a military-style weapon.
"Automatic weapon like that, had to be numbers of magazines or a very large drum, it sounded to me like a belt-fed weapon, a military style weapon and then to be shooting down, to use the analogy, it was like shooting fish in a barrel in that space," Gagliano said.
MGM Resorts, which owns the Mandalay Bay, tweeted that its thoughts and prayers were with the victims.
"This evening there was a tragic active shooter situation at the south end of the Las Vegas Strip. Law enforcement and emergency personnel responded quickly to the incident a secured the scene. Law enforcement requested that we put hotels in the vicinity on lockdown to ensure guest safety. We will provide more information as it becomes available," it said in a statement.
Facebook has set up a crisis response page to help people establish whether their loved ones are safe.