What we know so far:

  • At least 50 dead and another 53 injured in attack at LGBTQ nightclub.
  • Death toll expected to rise.
  • Worst mass shooting in U.S. history.
  • Killer identified as Omar Mateen, a U.S. citizen of Afghan descent.
  • U.S. President Barack Obama calls it ‘an act of terror and an act of hate.’
  • Islamic State claims responsibility.

What’s to be determined:

  • How and when did Mateen become radicalized?
  • Why was the gay nightclub chosen as the target of the violence?

When the shooting started, Jason Gonzalez knew exactly what he was hearing. The people around him began to run, screaming and trampling each other in a desperate rush for safety. He made it out a door and over a fence before he realized that his best friend was no longer with him.

“Nobody should ever have to go through this,” he said, standing outside Orlando Regional Medical Center, where the victims of Sunday morning’s mass shooting are being treated. His friend was shot twice in the back but will recover; other people he knows only in passing are dead.

Mr. Gonzalez, 33, shakily put a cigarette to his lips, his eyes wet with tears. “It’s really hard to take it in,” he said. “It doesn’t feel real.”

As night fell after the worst mass shooting in U.S. history, the country was plunged into a well of grief, horror and recrimination. In Orlando, families began the terrible process of mourning the 50 young men and women who were killed in a hail of gunfire at a popular nightclub.

Families were still waiting Monday morning, fearing the worst.

The shooting broke out at the Pulse nightclub around 2 a.m., after 29-year-old Omar Mateen entered the club with a powerful assault rifle and a handgun he had legally purchased days earlier.

Mr. Mateen, born in New York and of Afghan descent, had twice been investigated by the FBI, once after making “inflammatory comments to co-workers alleging possible terrorist ties” in 2013, and once because of possible links to an American suicide bomber in 2014.

FBI agent Ron Hopper said the federal agency investigated thoroughly and interviewed Mr. Mateen three times, but ultimately both investigations were closed.

Witnesses described a scene of confusion and chaos as the shooting unfolded, with some mistaking early sounds of gunshots for firecrackers or music, and masses of people running and screaming. There were more than 300 people in the club, which was holding its weekly Latin party. June is Pride Month in the LGBT community.

DJ Ray Rivera described hearing dozens of shots from the main area of the club, before escaping through a side gate.

“I saw bodies on the floor, people on the floor everywhere,” he said. “It was chaos, everybody trying to get out.”

The club posted a message on its Facebook page at about 3 a.m. saying, “Everyone get out of pulse and keep running.”

Mina Justice’s 30-year-old son, Eddie, texted her that he was hiding inside the bathroom. Then he wrote: “He’s coming.”

“The next text said: ‘He has us, and he’s in here with us,’ ” Ms. Justice said. “That was the last conversation.”

Police SWAT teams entered the club at about 5 a.m. Mr. Hopper said Mr. Mateen died after an exchange of gunfire with officers at the scene.

Early reports of 20 fatalities ballooned to confirmation that 50 people had been killed and another 53 injured, many of them in critical condition.

The crime scene was still being processed, the names of victims slowly released as bodies were identified, and families notified.

In a briefing from the White House on Sunday, President Barack Obama described the shooting as “an act of terror and an act of hate” against all Americans.

“This is a sobering reminder that attacks on any American, regardless of race, ethnicity, religion or sexual orientation, is an attack on all of us, and on the fundamental values of equality and dignity that define us as a country,” he said.

Mr. Obama said the full resources of the federal government are being made available for the investigation, and that he has directed no effort be spared “to determine what, if any, inspiration or association this killer may have had with terrorist groups.”

Mr. Hopper said Mr. Mateen called 911 before the massacre and made comments “general to the Islamic State.”

Islamic State’s Amaq news agency said Sunday that the attack was “carried out by an Islamic State fighter.”

Mr. Mateen lived in Port St. Lucie, Fla., about 200 kilometres from Orlando, and worked for the private security company G4S. Mr. Hopper said he was not currently under FBI investigation or surveillance.

Presumptive Republican presidential nominee Donald Trump took to Twitter on Sunday, writing: “Appreciate the congrats for being right on radical Islamic terrorism. I don’t want congrats, I want toughness & vigilance. We must be smart!”

Hillary Clinton, the presumptive Democratic nominee, released a statement calling to redouble efforts to defend the country, including by working with allies to go after international terror groups and countering recruitment attempts. She also called to keep guns out of the hands of “terrorists and violent criminals,” and expressed solidarity with the LGBT community.

“Hate has absolutely no place in America,” she wrote.

Patty Sheehan, Orlando’s first openly gay elected official, pledged her community would not be bowed by “thugs and murderers.”

“We as a gay, lesbian, bisexual, transgender community are a people who love. And if you think that you are going to stab at the heart of us by doing this horrible violent act, you’re not. Because we love,” she said. “We are a resilient people … We are going to show what the good heart of humanity is.”

In Canada, Prime Minister Justin Trudeau released a statement expressing shock and sadness.

“We stand in solidarity with Orlando and the LGBTQ2 community,” the statement read. “We grieve with our friends in the United States and Florida, and offer any assistance we can provide.”

Vigils were being planned across the country.

It is the 15th time Mr. Obama has spoken to the country after a mass shooting. He described it as “a further reminder of how easy it is for someone to get their hands on a weapon that lets them shoot people in a school or in a house of worship or in a movie theatre or in a nightclub.

“We have to decide if that’s the kind of country we want to be,” he said. “And to actively do nothing is a decision as well.”

The number of dead and injured far exceeded what were previously the country’s worst mass shootings. Thirty-two people were killed in a 2007 shooting at Virginia Tech, and 26, many of them children, died in a shooting at an elementary school in Newtown, Conn., in 2012.

Mr. Obama asked Americans to say a prayer for the victims and their families.

“In the face of hate and violence, we will love one another.”

JOANNA SLATER AND JANA G. PRUDEN
ORLANDO — The Globe and Mail
Published Sunday, Jun. 12, 2016 7:26AM EDT
Last updated Monday, Jun. 13, 2016 6:51AM EDT