The Islamic State claimed responsibility for the carnage.

In a sobering address to the nation hours after the shooting, President Obama called the attack “an act of terror and an act of hate.”

Orlando gunman Omar Mateen pledged allegiance to ISIS
“This is a sobering reminder that attacks on any Americans, 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.

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Victims of the Orlando nightclub mass shooting

The hate-filled attacker died in a shootout with police. Orlando Police Chief John Mina said the shooter was “organized and well prepared.”
Mateen was not under investigation at the time of the attack. He had been investigated by the FBI twice since 2013 for possible terrorist ties, FBI Assistant Special Agent in Charge Ron Hopper said.

Chaos at the scene of a mass shooting at Pulse Nightclub in Orlando early Sunday.

(UNIVISION FLORIDA CENTRAL / HAN/EPA)

In 2013, Mateen was investigated for making “inflammatory comments to co-workers alleging possible terrorist ties,” Hopper said. Nothing was confirmed. The following year he was investigated for ties to Moner Mohammad Abusalha, an American suicide bomber who killed himself in Syria