Oklahoma City police said that it appears there was a disturbance which led to "multiple shots being fired both inside and outside the event center."
The names and ages of those involved in the incident have not yet been released but authorities have confirmed that at least one person was killed in the altercation and 12 others have been injured.
The suspects are currently unknown at this time but several people have been detained, according to law enforcement.
"We are in the process of interviewing witnesses," authorities told ABC News. "We will provide more details when we get them."