A gunman wielding an assault-type rifle and a handgun took hostages and opened fire inside a crowded Florida nightclub, killing as many as 50 people and wounding 50 others.
The gunman — authorities identified him as 29-year-old Omar Mateen of Fort Pierce, Florida — died in a gunfight with SWAT officers, police said early June 12.
Police Chief John Mina also said the shooter had some sort of "suspicious device." He said the suspect exchanged gunfire with an officer working at the club around 2 a.m. June 12, then went back inside and took hostages.
Around 5 a.m., authorities sent in a SWAT team to rescue the hostages, and the suspect then died in a gunfight with those officers. Mina said police have not determined an exact number of casualties.
Florida Department of Law Enforcement Special Agent in Charge Danny Banks said during a news conference that the mass shooting is being investigated as an act of terrorism. He says authorities are looking into whether this was an act of domestic or international terror and if the shooter acted alone.
"This is an incident, as I see it, that we certainly classify as domestic terror incident," said Orange County Sheriff Jerry Demings.
Police had said previously on Twitter that there was a "controlled explosion" at the scene of the shooting at Pulse Orlando, which is known in the region as a gay dance club. Gay Days in Orlando, which brought more than 150,000 people to the area to celebrate LGBT Pride, had ended June 6. Saturday at the Pulse features known a Latin-theme night.
Mina Justice was outside the club early June 12 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,'" she said. "That was the last conversation."
Dozens of police vehicles, including a SWAT team, swarmed the area around the club. At least two police pickup trucks were seen taking what appeared to be shooting victims to the Orlando Regional Medical Center
Pulse Orlando posted on its own Facebook page around 2 a.m.: "Everyone get out of pulse and keep running."
Pulse Orlando 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."
Police said local, state and federal agencies were investigating.
The incident follows the fatal shooting earlier in the week of 22-year-old singer Christina Grimmie, who was killed after her concert in Orlando by a 27-year-old Florida man who later killed himself. Grimmie was a YouTube sensation and former contestant on "The Voice."
Jon Alamo said he was at the back of one of the club's rooms when a man holding a weapon came into the front of the room.
"I heard 20, 40, 50 shots," Alamo said. "The music stopped."
Club-goer Rob Rick said it happened around, 2 a.m., just before closing time.
"Everybody was drinking their last sip," he said.
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 in the back where only workers are allowed. People inside were able to then escape through the back of the club.
Christopher Hansen said he was in the VIP lounge when he started hearing gunshots. He continued to hear shooting even after he emerged, where police were telling people to back away from the club. He saw injured people being tended to 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."
The Associated Press contributed to this report. WiG editor Lisa Neff contributed to this report.