Orlando, Florida (CNN)An American-born man who’d pledged allegiance to ISIS gunned down 50 people early Sunday at a gay nightclub in Orlando — the deadliest mass shooting in the United States and the nation’s worst terror attack since 911, authorities said.
* The gunman, Omar Mateen, 29, of Fort Pierce, Florida, was interviewed by the FBI in 2013 and 2014 but was not found to be a threat, the FBI said.
* Mateen called 911 shortly before the attack to pledge allegiance to ISIS and mentioned the Boston Marathon bombers, according to a U.S. official.
* Orlando police shot and killed Mateen.
Mateen carried an assault rifle and a pistol into the packed Pulse club about 2 a.m. Friday and started shooting, killing 50 people and wounding at least 53, police said.
After a standoff of about three hours — while people trapped inside the club desperately called and messaged friends and relatives — police crashed into the building with an armored vehicle and killed Mateen.
“It appears he was organized and well-prepared,” Orlando Police Chief John Mina said early Sunday. Authorities say they haven’t found any accomplices.