Is ISIS Responsible For The Orlando Shooting? The Gunman's Motive Is Unclear

Update: In a press conference Monday morning, Orlando police confirmed that 49 people had been killed and 53 injured early Sunday morning at Orlando's Pulse gay nightclub in the deadliest mass shooting in recent U.S. history. After opening fire on the crowd, an individual named Omar Mateen had taken hostages and was ultimately killed in a stand-off with police; Mateen had called 911 and pledged allegiance to the Islamic State shortly before the massacre. Orlando mayor Buddy Dyer declared a state of emergency, and the massacre is being investigated as an act of terrorism.

The victims' names were released by the city of Orlando on its website as their next of kin were informed. Here are some ways to help the Orlando shooting victims and their loved ones; you can also donate to the victims' fund, as well as express your solidarity with the LGBTQ community by posting a tribute online. You can also attend a vigil near you to honor the victims.

Earlier: Early Sunday morning, a shooting in an Orlando, Florida nightclub, Pulse, left "mass casualties," according to police. With approximately 20 dead and twice as many injured, police are calling the attack an act of terrorism, and are currently investigating whether ISIS is responsible for the shooting, according to ABC News.

Multiple sources are reporting the deceased shooter "an American-born citizen with no apparent criminal history," but that he may have had ties with Islamic terrorism. The shooter was killed at the scene after a SWAT team entered the club. According to the LA Times, investigating officials did not elaborate on why they believe he may have had involvement with radical Islam.

Officials did confirm that that the shooter acted alone in his attack on the gay club Sunday morning, armed with an assault rifle, a handgun, and an unspecified "suspicious device." Bustle will continue to update as more information is released.