For those of you waking up to this story, here is a break down of what we know about the Orlando shooting so far.A gunman named as Omar Mateen killed 50 people and left 53 others injured, many seriously, in a 2am attack on LGBT nightclub the Pulse, in Orlando, Florida. After an hours-long standoff, police stormed the building, killed the gunman and rescued about 30 hostages.The massacre is the worst mass shooting in American history, and like several recent mass shootings was committed by a man with an AR-15 assault rifle.Barack Obama declared the attack “an act of terror and an act of hate”.Authorities released the first names of victims, after notifying kin.The first fifteen people named were Edward Sotomayor Jr, Stanley Almodovar III, Luis Omar Ocasio-Capo, Juan Ramon Guerrero, Eric Ivan Ortiz-Rivera, Peter O. Gonzalez-Cruz, Luis S. Vielma, Kimberly Morris, Peter O. Gonzalez-Cruz, Luis S. Vielma, Kimberly Morris, Eddie Jamoldroy Justice, 3Darryl Roman Burt II, Deonka Deidra Drayton, Alejandro Barrios Martinez, Anthony Luis Laureanodisla, Jean Carlos Mendez Perez, Franky Jimmy Dejesus Velazquez.Mateen was a US citizen from Fort Pierce, Florida. He was known to the FBI and the subject of two investigations into terror links in 2013 and 2014. Those investigations were deemed inconclusive and closed.The shooter called 911 before the attack and spoke with an emergency operator in “general to the Islamic State”. While Isis has claimed responsibility for the attack US officials say there’s no immediate evidence linking the militant group to the massacre. Mateen bought a long gun and a handgun legally in the last week, a spokesperson for the Bureau of Alcohol, Tobacco & Firearms said. Questions have been raised over why he was allowed to buy the weapons.His ex-wife said Mateen was “obviously disturbed”and that he beat her and held her hostage during their short marriage.Survivors and the families of victims recalled horrific stories of how the attack unfolded, and many waited in fear and anticipation to learn whether their loved ones were victims.Donald Trump has postponed a rally in New Hampshire on Monday in the wake of the attacks. But he will press ahead with a speech on “the threats facing all Americans.”Renewed debate over gun control has started, with Marco Rubio saying firearms legislation would not have prevented the attack.Muslim American leaders, LGBT groups, Pope Francis and others condemned the horrific attack, and urged Americans to rally together. The FBI solicited the public for tips to aid the investigation, blood banks asked for donations around the US, and a fundraising campaign for victims’ medical bills raised $416,000. Authorities set up hotlines for information and campaigns for donations.A US official told the Guardian the attack may have been a “massive hate crime”. Mateen’s father told NBC News that his son had become enraged by a gay couple kissing.