Orlando, Florida (TIP): In the worst of mass shootings in the history of America, a lone wolf gunman killed 50 at Pulse club, a popular gay night bar in Orlando, on Sunday, June 12, 2016

Another 53 were injured; either because of the gunshot injuries or because of the stampede that followed the gunmen’s opening fire.

It may be recalled that the earlier worst shootings at Virginia Tech in 2007 and Sandy Hook Elementary School in 2012, with 32 and 27 killed.

The incident is being investigated according to sources as one related to Islamic terrorism.

The gunman who was also killed has been identified as Omar Saddiqui Mateen, a U.S. citizen of Afghan descent.

The suspect, 29 is from Fort Pierce, Florida, as per the official briefing. A law enforcement source told that Mateen worked as a private security guard. He rented a car and drove to Orlando to carry out the attack, as reported by CNN.

“It appears he was organized and well-prepared,” Orlando Police Chief John Mina said early Sunday. The shooter had an assault-type weapon, a handgun and “some type of (other) device on him.”

Orlando Mayor Buddy Dyer said he had declared a state of emergency for the city and has requested the governor do the same for the state.

The incident began at about 2 a.m. ET and ended at about 5 a.m.

President Obama is expected to make a statement at 1:30 p.m. ET, the White House says. Vice President Joe Biden has also canceled his planned appearance at a campaign fundraiser in Florida tonight.

At 1:30pm ET, @POTUS will deliver a statement on the tragic shooting in #Orlando. Watch live: https://t.co/k6QWAbrHAh

— The White House (@WhiteHouse) June 12, 2016

The presumptive Republican and Democratic presidential nominees shared their thoughts:

Desperté con la devastadora noticia de FL. Mientras esperamos más información,mis pensamientos están con los afectados de este horrible acto

— Hillary Clinton (@HillaryClinton) June 12, 2016

Really bad shooting in Orlando. Police investigating possible terrorism. Many people dead and wounded.

— Donald J. Trump (@realDonaldTrump) June 12, 2016

Horrific incident in FL. Praying for all the victims & their families. When will this stop? When will we get tough, smart & vigilant?

— Donald J. Trump (@realDonaldTrump) June 12, 2016

How the shooting began and led to a hostage situation…

The shooting began around 2 a.m., and an officer who was working at the club responded, Mina said. The officer engaged in a shootout outside the club, after which the gunman ran into the club.

“That turned into a hostage situation,” Mina said.

Authorities were getting calls from people inside the club but away from the gunman, the chief said.

“There were just bodies everywhere… in the parking lot, they were tagging them – red, yellow – so they knew who to help first and who not to. Pants down, shirts cut off, they had to find the bullets. Just blood everywhere,” an eyewitness told IANS.

CCTV camera footage from the scene showed dozens of emergency vehicles at the scene and people being treated on the pavements.

Some of the injured were reportedly brought to the Orlando Regional Medical Center in police pick-ups.

Some witnesses said they heard as many as 40-50 gunshots as the incident unfolded.

More than 100 people were reported to have been enjoying a Latin-themed night in the club, which calls itself the hottest gay bar in the city, when the attack began.

Hours before the shooting, the club urged partygoers to attend its “Latin flavor” event Saturday night. After the shooting began, the club posted a terse warning on its Facebook page: “Everyone get out of Pulse and keep running.”

The shooter opened fire at around 02.00 a.m. (local time) as the club night was coming to a close.

“We heard rapid fire go off. In the room I was in, people went down to the floor. I wasn’t able to see the shooter or people get hurt, at some point, there was a brief pause, and a group of us got up and went to the exit that leads to the patio area outside. We found an exit and after that… I just ran,” Anthony Torres, an eyewitness said.

He also heard people screaming that others in the nightclub were dead.

According to the Mass Shooting Tracker, there were 372 mass shootings — defined as a single incident that kills or injures four or more people — in the US in 2015. Some 475 people were killed and 1,870 wounded.

The latest incident comes as Orlando is still reeling from the fatal shooting on Friday night of 22-year-old singer Christina Grimmie following a concert in the city.

She was signing autographs when she was shot by 26-year-old Kevin James Loibl, who then killed himself. It is not clear what Loibl’s motive was.

Video from the scene of crime / Youtube / Social Media