What we know so far
America's worst-ever mass shooting begun at 2am in Orlando.
Omar Mateen, 29, who made a pledge of allegiance to Isil, was heavily armed.
He opened fire then went outside, shot at police, and returned inside to take 30 hostage.
50 people were killed inside Pulse nightclub, a gay venue.
Police ended the siege around 5am, using an armoured vehicle to storm the building.
Mateen's father, born in Afghanistan, says his son was angered at seeing two men kissing.