Mass Shooting Occurs at Madden Tournament; Multiple Fatalities Reported

Update: This story has been updated following the Jacksonville Sheriff's Office's press conference on the incident. Official details are below.
Update 2: Updated again on Sunday evening with an additional statement from Electronic Arts.
A gunman opened fire at a Madden Championship Series tournament event in Jacksonville, Florida today.
At the first event during the Madden tournament season, a gunman opened fire on the crowd, firing at least a dozen shots, per a clip of the Twitch broa