Authorities have identified the shooter as 29-year-old Omar Mateen of Fort Pierce, Florida.
The father of the man named as the shooter in a massacre at a gay Florida nightclub says he's in shock and that he wasn't aware of anything his son might have been planning.
Seddique Mateen is the father of Omar Mateen. Seddique Mateen told NBC News that his son got angry when he saw two men kissing in Miami a couple of months ago and thinks that may be related to the shooting.
Seddique says: "We are saying we are apologizing for the whole incident. ... We are in shock like the whole country."
The father also says the incident has nothing to do with religion.
Authorities were investigating it as an act of terrorism.
At least 53 other people were hospitalized, most in critical condition, officials said.
“I think we will see the death toll rise,” said Dr. Mike Cheatham a trauma surgeon at Orlando Regional Medical Center.
Mayor Buddy Dyer said all of the dead were killed with the assault rifle.
Officials say the shooter was killed, and that they're investigating whether the incident was an act of terrorism.
In a 911 call from the club, Mateen professed allegiance to the leader of the Islamic State, Abu Bakr al-Baghdadi.
Mateen was a U.S. citizen born in New York. His ex-wife said his family was from Afghanistan.
Authorities say Mateen was not under surveillance, but that in 2014, they discovered he had ties to an American suicide bomber. They said the ties were minimal and they didn't think he represented a threat at the time.
They say he also made inflammatory comments to co-workers in 2013.
Authorities also say Mateen legally purchased at least two firearms within the past week or so.
Security company G4S said in a statement to the Palm Beach Post that he had been an employee of the company since September 10, 2007.