Orlando Nightclub Shooting: The Worst in US History

The gunman who opened fire inside a crowded nightclub here early Sunday morning, launching a rampage that killed 50 people and injured 53 others in the deadliest shooting spree in the country's history, had pledged allegiance to the Islamic State before the attack, according to US law enforcement officials.

Authorities in Orlando said Sunday that the siege at Pulse, a popular gay bar and dance club, was quickly deemed an act of domestic terrorism. Police said that after a first round of gunshots at 2am local time, the shooter took hostages for about three hours, until officers who went inside to rescue these people killed the gunman in a shootout. It was not immediately clear if the death toll included the gunman.

The gunman, identified as 29-year-old Omar Mateen, apparently made a 911 call before the attack identifying himself and pledging allegiance to the leader of the Islamic State, according to U.S.

Mateen also made a reference to the 2013 bombing of the Boston Marathon during this call. He was also investigated by the FBI in 2014 but it was closed the same year. 

Until Sunday, the 2007 rampage at Virginia Tech - which saw 32 people killed and 30 others injured - was the country's worst mass shooting.

Orlando Police Chief John Mina said "It's absolutely terrible...Fifty victims in one location, one shooting, is absolutely one of the worst tragedies we've seen."

In the aftermath of the shooting, officials said many things remained unknown, including:

- A possible motivation for the gunman and more about his background.

- The final death toll.

- Identities of all of the people killed and injured.

- A clearer timeline of what happened inside the club and when all of the victims were injured.

One relative said that Mateen's family was in shock after being told on Sunday morning about his involvement. This relative said Mateen's family was very sorry about what had happened.

The White House said President Barack Obama was briefed on the incident Sunday.

"Our thoughts and prayers are with the families and loved ones of the victims," the White House said in a statement. "The President asked to receive regular updates as the FBI, and other federal officials, work with the Orlando Police to gather more information, and directed that the federal government provide any assistance necessary to pursue the investigation and support the community."

The horrific incident began as Saturday gave way to Sunday at the crowded club. Around 2 a.m., Pulse Orlando posted an urgent message on Facebook: "Everyone get out of pulse and keep running."

Within minutes of the shooting, police vehicles and a SWAT team descended on the club, which had more than 300 people inside as the shooting began.

"I was there," Ricardo J. Negron posted on the club's Facebook page several hours later. "Shooter opened fire @ around 2:00am. People on the dance floor and bar got down on the floor and some of us who were near the bar and back exit managed to go out through the outdoor area and just ran. I am safely home and hoping everyone gets home safely as well."

An officer working at the club exchanged fire with the gunman, authorities said. It was then, according to police, that the incident developed into "a hostage situation."

Authorities said the man was armed with an "suspicious device," in addition to his guns, Mina, the police chief, told reporters.

Read more at NZHerald.co.nz