Flower Mound evacuated Town Hall on Tuesday afternoon because of a tweeted bomb threat.
Police said officials learned of the bomb threat from someone who saw it on Twitter and notified the authorities.
Town Hall, the Shirley Viorin Social Senior Center and the Cross Timbers YMCA were evacuated by 1:30 p.m. Eastbound traffic on Cross Timbers Road was diverted by 1:40 p.m.
Investigators quickly identified 18-year-old Matt Pumphrey, of Flower Mound, in connection with the hoax.
Pumphrey was arrested at 2:18 p.m. and charged with making a terroristic threat, a Class A misdemeanor.
He also had tweeted: "That tweet was a complete joke. Im (sic) sorry for tweeting it."
The evacuated buildings reopened at about 2:30 p.m.
The investigation of the tweeted threat is ongoing, Flower Mound police said.