About 20 people were killed and at least 42 people were wounded when a gunman armed with an assault-style rifle, a handgun and possibly an explosive device opened fire inside a gay nightclub in Orlando, Fla., at about 2 a.m. on Sunday, Police Chief John Mina said.
The police classified the attack at the Pulse nightclub as a “terror incident.” Local and federal authorities were investigating, and the F.B.I. set up a hotline for tips.
The police and the federal authorities said they were pursuing several angles in the terrorism investigation, both overseas and in the United States.
The gunman, who was found dead inside the club and whose name had not been released, was not from the Orlando area and was organized and well prepared, the police said.
It was one of the three deadliest shootings in United States history: 32 people were killed at Virginia Tech in 2007, and 26 died in Newtown, Conn., in 2012.
President Obama was briefed on the attack by Lisa Monaco, assistant to the president for homeland security and counterterrorism, the White House said, and asked to receive regular updates on the investigation.
The gunman was shot by SWAT officers who stormed Pulse, one of the largest gay clubs in Orlando, at about 5 a.m. The officers were attempting to rescue dozens of people who were being held hostage, Chief Mina said.
The chief said it was difficult to assess the number of people at the club who had been killed because many of the bodies had not yet been removed.
The police were searching the club for other explosives that the gunman may have planted during his assault.
A member of the Orange County sheriff’s department at the scene of a shooting in Orlando, Fla., on Sunday. Credit Phelan M. Ebenhack/Associated Press
The shooting began inside the club, Chief Mina said, and continued outside when an officer working at Pulse attempted to confront the gunman. The gunman then ran back into the club, resumed shooting and took hostages.
At 5 a.m., Chief Mina said, the police decided to attempt a rescue, detonating two explosives to distract the gunman and to help clear the club.
“With that advantage,” the chief said, nine officers moved into the club to confront the gunman. In the ensuing shootout, one of the officers was slightly wounded, saved by his Kevlar helmet, the authorities said.
“We rescued about 30 people,” Chief Mina said. During the rescue and shootout, officers with the SWAT team — using an armored vehicle — entered the club and hurried people to safety. Many of them had sought shelter in other sections of the sprawling club.
The survivors escaped under the cover of what the police called the two “discretionary explosions.”
The wounded were taken to three hospitals in the area. Most were taken to Orlando Regional Medical Center, the area’s chief trauma center, which is three blocks from the club.
On its Twitter feed, the Orlando Police Department asked other residents to “stay away from area” and said that it was seeking support from state and federal agencies. Later, employees in the area were asked to stay home if possible.
The club itself posted a message on its Facebook page about 3 a.m.: “Everyone get out of pulse and keep running.”
People streamed out of the club into a chaotic situation with little idea of where to go. “Cops were saying, ‘Go, go, clear the area,’” Christopher Hansen told an Orlando TV station. “You don’t know who’s what and who’s where.”
As the sun came up, video shot from a helicopter showed a situation that seemed to be under control, although windows on one side of the club appeared to be shot out.
Phone camera videos show police cars, ambulances and other emergency vehicles outside the club on South Orange Avenue in downtown Orlando. Streets around the club were shut down for several blocks.
Dozens of officers, paramedics and firefighters from the Orlando police, the Orange County Sheriff’s Office, the F.B.I. and three fire departments were called to the scene.
“This will have a lasting effect on our community,” Chief Mina said. “We are a strong community.”
In the hours after the shooting, local television stations broadcast camera phone videos that captured the chaos at and near Pulse. One of the videos clearly captured the rescue attempt. Shots could be heard as men and women ran from the nightclub.
Some of the clubgoers told local television reporters that the music was so loud that it was difficult at first to distinguish the shots from the pulsing beat.
More than 100 people were believed inside the club when the shooting began.
Orlando Regional Medical Center was placed on lockdown after receiving the first of the victims. “Only essential workers are being allowed access into the building,” the hospital said in a statement.
“Out of an abundance of caution, Arnold Palmer Hospital and Winnie Palmer Hospital have also been placed on lockdown,” the statement added.
On Pulse’s Facebook page, club officials promised to post updates as they came in: “As soon as we have any information, we will update everyone.”