Authorities are working to identify the nearly 50 people killed in a gay nightclub shooting massacre in Orlando.
It happened in the early hours of Sunday at Pulse nightclub, where a man opened fire while 320 people were inside, killing 50 and injuring 53.
Investigators said the gunman is identified as Omar Mateen, 29, and was shot and killed by police upon entering the nightclub where he was holding an estimated 30 people hostage.
Orlando police said Monday morning that 48 of the 49 victims had been identified. They have notified about 24 families and said that notifying family is their highest priority today. They are posting the names of the victims on a website created following the shooting and said the names are only being posted once they are able to confirm that next of kin has been notified of their passing.
"Our primary mission is to notify next of kin" getting briefed at News Conference in Orlando live updates at 12pm pic.twitter.com/u35UqiFM8j— Liz Artz (@LizArtzWSB) June 13, 2016
Orlando Mayor Buddy Dyer said of the victims, 39 were killed at the club and 11 people died at hospitals.
After the shooting began, Mateen called 911 to pledge his allegiance to ISIS, according to law enforcement officials.
Authorities were investigating the attack as an act of terrorism. The gunman's father recalled that his son recently got angry when he saw two men kissing in Miami and said that might be related to the assault.
All of the dead were killed with the assault rifle, according to Rep. Alan Grayson, a Florida Democrat.
"There's blood everywhere," Orlando Mayor Buddy Dyer said.
Witnesses described a chaotic scene when the gunfire began shortly before the club known as Pulse was to close.
"Some guy walked in and started shooting everybody. He had an automatic rifle, so nobody stood a chance," said Jackie Smith, who had two friends next to her get shot. "I just tried to get out of there."
Mateen's ex-wife said his family was from Afghanistan but that her ex-husband was born in New York. His family later moved to Florida.
The shooter in 2013 made inflammatory comments to co-workers, and Mateen was interviewed twice, Hopper said. He called those interviews inconclusive.
“Everybody was having fun. I hear a loud ‘bang!’ You just see people drop. You hear yelling and more commotion. I’m getting covered in blood.” -- witness Dontei Martinez.
In 2014, Hopper said, officials found that Mateen had ties to an American suicide bomber. He described the contact as minimal, saying it did not constitute a threat at the time.
Mateen purchased at least two firearms legally within the last week or so, according to Trevor Velinor of the Bureau of Alcohol, Tobacco and Firearms.
The suspect exchanged gunfire with 14 police officers at the club, which had more than 300 people inside.
At one point, he took hostages, Police Chief John Mina said. Around 5 a.m., authorities sent in a SWAT team to rescue the hostages.
Pulse posted on its own Facebook page around 2 a.m.: "Everyone get out of Pulse and keep running." Just before 6 a.m., the club posted an update: "As soon as we have any information, we will update everyone. Please keep everyone in your prayers as we work through this tragic event. Thank you for your thoughts and love."
"We are dancing and all of a sudden it just started like a rolling thunder, loud and everything went black." -- Orlando resident Brand White, who was shot.
Christine Leinonen said she "just happened" to wake up at 3 a.m., about an hour after the shooting started at Pulse.
She saw her son Christopher's friend post on Facebook that there had been a shooting at the club and that he didn't "know where his friends were."
Leinonen told ABC News that her son's friend, Brandon, told her he saw that Christopher's boyfriend "had multiple gunshots and was being taken by the ambulance but he never saw Christopher [come] out. And we haven't been able to call him or text him."
"They said there's a lot of dead bodies in the club and that it's a crime scene ... so it could be hours and hours before we find out. The hospital said there are some bodies at the hospital that came in and they died and they're not identifiable yet either," Leinonen said.
"The place where they were attacked is more than a nightclub — it is a place of solidarity and empowerment where people have come together to raise awareness, to speak their minds, and to advocate for their civil rights." -- President Barack Obama
She said she was very "proud" of her son who had been active in the gay community for years. Leinonen said that Christopher established the Gay Straight Alliance at his high school and received a humanitarian award as a result.
In addition to the assault rifle, the shooter also had some sort of "suspicious device," the police chief said.
In the immediate aftermath of the attack, police departments across the country stepped up patrols in neighborhoods frequented by the LGBT community.
Authorities were looking into whether the attack was an act of domestic or international terrorism, and if the shooter acted alone, according to Danny Banks, an agent with the Florida Department of Law Enforcement.
"This is an incident, as I see it, that we certainly classify as domestic terror incident," Orange County Sheriff Jerry Demings said.
"Tonight, we had a crime that will have a lasting effect on our community," -- Orlando Mayor Buddy Dyer
A federal law enforcement official with knowledge of the investigation said Mateen was known to the FBI before the nightclub attack and had been looked at by agents within the last few years. The official was not authorized to discuss the investigation publicly and spoke on condition of anonymity.
The matter for which he came under investigation was "open and closed pretty quickly," the official said.
The gunman was a security guard with a company called G4S. In a 2012 newsletter, the firm identified him as working in West Palm Beach.
In a statement sent Sunday to the Palm Beach Post, the security company confirmed that he had been an employee since September 2007.
State records show that Mateen had held a firearms license since at least 2011. It was set to expire in 2017.
President Barack Obama called the shooting an "act of terror" and an "act of hate" targeting a place of "solidarity and empowerment" for gays and lesbians.
He urged Americans to decide whether this is the kind of "country we want to be."
Authorities said they had secured a van owned by the suspect outside the club.
Mother of man who was at Orlando club: "There's a lot of dead bodies at the club...they can't identify anybody." https://t.co/KXKy7t4Bpr— ABC News (@ABC) June 12, 2016
Meanwhile, a SWAT truck and a bomb-disposal unit were on the scene of an address associated with Mateen in a residential neighborhood of Fort Pierce, Florida, about 118 miles southeast of Orlando.
Relatives and friends, many in tears, gathered outside the hospital to learn the fate of loved ones.
Smith did not know the conditions of her wounded friends. She came out of the hospital and burst into tears.
Christine Leinonen drove to Orlando at 4 a.m. after learning of the shooting from a friend of her 32-year-old son, Christopher Leinonen, who was at Pulse and is missing.
She had not heard from her son and feared the worst.
"These are nonsensical killings of our children," she said, sobbing. "They're killing our babies!"
She said her son's friend Brandon Wolf survived by hiding in a bathroom and running out as the bullets flew.
A woman who was outside the club early Sunday was trying to contact her 30-year-old son, Eddie, who texted her when the shooting happened and asked her to call police. He told her he ran into a bathroom with other club patrons to hide. He then texted her: "He's coming."
"The next text said: 'He has us, and he's in here with us,'" Mina Justice said. "That was the last conversation."
A bartender said she initially thought the gunshots were music. But after a second shot, there was a pause, followed by more shots. That's when Tiffany Johnson realized something was wrong.
Johnson said people dropped to the ground and started running out of the club. She ran to a fast-food restaurant across the street and met one of her customers who let her get in his car. They drove away.
Club-goer Rob Rick said the shooting started just as "everybody was drinking their last sip."
He estimated more than 100 people were still inside when he heard shots, got on the ground and crawled toward a DJ booth. A bouncer knocked down a partition between the club area and an area where only workers are allowed. People were then able to escape through the back of the club.
Christopher Hansen said he was in the VIP lounge when he heard gunshots. He continued to hear shooting even after he emerged and saw the wounded being tended across the street.
"I was thinking, 'Are you kidding me?' So I just dropped down. I just said, 'Please, please, please, I want to make it out,'" he said. "And when I did, I saw people shot. I saw blood. You hope and pray you don't get shot."
Content from WFTV, ABC News and The Associated Press were used in this article.
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