In Pictures: When a Popular Gay Nightclub in Orlando Turned Deadly

How the heart-wrenching Orlando shooting unfolded.

Rachel Henry (left) and Selene Arciga, kiss to show their solidarity with the victims of the Orlando shooting vitimcs during a candlelight vigil in front of the White House in Washington, Sunday, June 12, 2016. (Photo: Manuel Balce Ceneta/AP)

It had been an evening of drinking, dancing and drag shows. After hours of revelry, the party-goers crowding the gay nightclub known as Pulse took their last sips before the place closed.

Jillian Amador hugs a friend at Orlando Police Department headquarters after a shooting at Pulse nightclub early Sunday, 12 June 2016 in Orlando. (Photo: Naseem Miller/Orlando Sentinel via AP)

That’s when authorities say Omar Mateen emerged, carrying an AR-15 and spraying the helpless crowd with bullets. Witnesses said he fired relentlessly – 20 rounds, 40, then 50 and more. In such tight quarters, the bullets could hardly miss. He shot at police. He took hostages.

This undated image provided by the Orlando Police Department shows Omar Mateen, the shooting suspect at the Pulse nightclub in Orlando, Florida, 12 June. (Photo: AP)

Authorities immediately began investigating whether the assault was an act of terrorism and probing the background of Mateen, a 29-year-old American citizen from Fort Pierce, Florida, who had worked as a security guard.

When the gunfire finally stopped, 50 people were dead and dozens critically wounded in the deadliest mass shooting in modern US history. Mateen, who authorities said had pledged allegiance to Islamic State in a 911 call shortly before the attack, died in a battle with SWAT team members.

Investigators from the office of the medical examiner investigate on the west side of Pulse nightclub where a gunman opened fire on Sunday morning, 12 June 2016, in Orlando, Fla. (Photo: Doug Clifford/The Tampa Bay Times via AP)

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.

(Photo: AP)

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.

At least 53 people were hospitalised, most in critical condition, officials said. A surgeon at Orlando Regional Medical Center said the death toll was likely to climb.

Annette Stubbs, a pastor at a local church, prays for victims a few blocks from a crime scene at the nightclub where a mass shooting took place the night before in Orlando, Fla., Sunday, 12 June 2016. (Photo: AP)

“There’s blood everywhere,” Orlando Mayor Buddy Dyer said.

Mina Justice shows a text message she received from her son Eddie Justice at Pulse nightclub during a fatal shooting in Orlando, Fla., Sunday, 12 June 2016. Justice hasn’t heard from her son since the messages. (Photo: AP)

Donors give blood at the OneBlood blood bank in Orlando, Fla., after the shooting involving multiple fatalities at a nightclub, Sunday, 12 June 2016. (Photo: AP)

Orlando City Commissioner Patty Sheehan, right, embraces Terry DeCarlo, an Orlando gay rights advocate, as they arrive on the scene of a mass shooting in Orlando, Fla., Sunday, 12 June 2016. (Photo: AP)

People grieve outside a Hampton Inn & Suites hotel, which turned into a hub for families and friends waiting to hear about loved ones because of its proximity to the Orlando Regional Medical Center, in the wake of the shooting. (Photo: AP)

Judy Rettig, left, cries with her partner of 43 years, Christine Santoro, while taking part in a prayer vigil at the Joy Metropolitan Community Church after the Pulse Orlando nightclub shooting on Sunday, 12 June 2016, in Orlando, Fla. (Photo: AP/Chris O’Meara)

Juan Mantilla, 42, of Miami Beach, Fla., left, stands with his partner during a vigil in memory of the victims of the Orlando mass shooting, Sunday, 12 June 2016, in Miami Beach, Fla. (Photo: AP)

(With inputs from AP)