Hundreds of thousands are posting on social media outlets like Twitter and Facebook, commenting on the shooting.
Popular hashtags include #PrayForOrlando, #Pulse, #PulseShooting, #PulseNightclub.
The shooter's father said that the shooter was angry recently after seeing two men kiss. Homophobia is deadly. #PulseShooting— deray mckesson (@deray) 12 июня 2016 г.
Early Sunday, presumptive presidential nominees Hillary Clinton and Donald Trump also weighed in on Twitter.
Sad and tragic day. Thoughts and prayers with loved ones of #PulseNightclub victims.— Vali Nasr (@vali_nasr) 12 июня 2016 г.
Clinton expressed condolences.
Woke up to hear the devastating news from FL. As we wait for more information, my thoughts are with those affected by this horrific act. —H— Hillary Clinton (@HillaryClinton) 12 июня 2016 г.
While Trump called the Orlando shooting a demonstration of radical Islamic terrorism and called for toughness, smartness and vigilance.
Is President Obama going to finally mention the words radical Islamic terrorism? If he doesn't he should immediately resign in disgrace!— Donald J. Trump (@realDonaldTrump) 12 июня 2016 г.
"Horrific incident in FL. Praying for all the victims & their families. When will this stop? When will we get tough, smart & vigilant?… Appreciate the congrats for being right on radical Islamic terrorism, I don't want congrats, I want toughness & vigilance. We must be smart!" Trump said on his Twitter account.
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) 12 июня 2016 г.
Many called for toughening of gun control in the country. The hashtag is #GunControlNow.
How many more lives have to be taken away before you realize this is a real issue? #GunControlNow— Diana (@TaylenaCimLM) 12 июня 2016 г.
U.S. Congress Representatives:— Dened Rey (@Hajabeg) 12 июня 2016 г.
Your prayers won't make your people suddenly bulletproof. What your people need is ACTION and #GunControlNow
On June 12, 2016 29-year-old US citizen Omar Mateen opened fire at Pulse gay nightclub in downtown Orlando, killing 50 people and injuring at least 53.
I am gay and I am not afraid. Love conquers all. #PrayforOrlando— Ricky Martin (@ricky_martin) 12 июня 2016 г.
He was eventually shot by a SWAT team after briefly taking some hostages.
The massacre has become the deadliest in recent US history.