A gunman opened fire in Orlando's Pulse nightclub early morning Sunday , killing approximately 50 people and injuring another 53 . Clubbers were enjoying an evening at Pulse , which describes itself as " the hottest gay bar in Orlando , " when shots started to go off around 2 am. A hostage situation occurred , and didn't end until authorities used a vehicle armed to teeth to break down the door of the building and kill the gunman at around 5 am . Sunday morning's attack surpasses the shootings at Virginia Tech in 2007 and Sndy Hook Elementary School in 2012 to become the worst mass shooting in US history . Authorities have identified the shooter as 29-year-old Omar Saddiqui Mateen from Fort Pierce , about 120 miles southeast of Orlando . CNN reports Mr. Mateen was previously trained as a security guard . The federal government and FBI " have suggestions the individual has leanings towards Islamic terrorism , but right now we can't say definitely , " says Ron Hopper , assistant special agent of FBI's Orlando bureau . But Mateen's connection to Islamic terrorism has not been proven , leading authorities to also investigate the shooting as a possible hate crime against the LGBT community . The Orlando blood donation facility tweeted that the bank was in " urgent need " of donations Sunday morning following the shooting . But within hours , they announced their bank was at capacity due to the long lines of volunteers who showed up to donate . However , after the initial tweet at 10:40 Sunday morning , criticisms of the United States' stand on blood donation by the LGBT community resurfaced on social media from those who wanted to help but were prohibited due to their sexuality . " It's legal to buy an AR-15 assault rifle . It's illegal for a gay man to donate blood to victims of the massacre . The world makes no sense . " said John Barcus . ( LGBT : a community of four types of people ; lesbian , gay , bisexual , transgender .) What do we know about the shooting from the passage ?
It lasted for more than four hours . 50 people were killed during this scary attack . This is the second worst shooting on American soil . The police had to rely on heavy equipment to kill the gunman .