A Georgia man who made terroristic threats to "shoot up" Hartsfield-Jackson International Airport on Oct. 20 was arrested after family tipped off law enforcement about the planned attack, authorities said.

"A tragedy was indeed averted," Atlanta Police Chief Darin Schierbaum said at a news conference. "We are here today briefing you on a success, and not a tragedy, because a family saw something and said something... That is how it should work."

The suspect, identified as Billy Jo Cagle, 49, of Cartersville, Georgia, was charged with terroristic threats, possession of a firearm during commission of a felony, criminal attempt to commit aggravated assault and possession of a firearm by a convicted felon.

Schierbaum said family members called police in Cartersville about 9:40 a.m. ET and informed them that Cagle was streaming on social media and headed to the airport to "shoot it up." Cartersville police then alerted authorities in Atlanta to the situation.

While family members told authorities that Cagle had an assault rifle and was experiencing mental challenges, Schierbaum said Atlanta police didn’t know that he had already arrived at the airport’s domestic south terminal at 9:29 a.m. ET