Staff Photo by Joy Luckachick McMinn County Sheriff Joe Guy addresses the media concerning the arrest of three suspects in the case of objects being thrown from bridges at motorists along Interstate 75. Cleveland Mayor Tom Rowland listens in the background.

ATHENS, Tenn. -- Three men who are suspected of vandalism that caused more than $100,000 in damage to the new Cleveland airport also are suspected of tossing items off Interstate 75 overpasses in McMinn County, hitting vehicles below, authorities said Thursday.

Through an undercover investigation and a sting operation involving local and state police, the men from McMinn were arrested late Wednesday night and charged in connection with vandalism at the airport and at another construction site in Athens, Tenn.

More charges are expected, police said.

Casey Thomas, 18, of Athens; Barry Burbank, 20, of Sweetwater, Tenn.; and Jeremy Mulkey, 19, of Athens, admitted to throwing mailboxes and a fan motor off overpasses at least four times, McMinn County Sheriff Joe Guy said.

"This is not a prank," he said. "It's a dangerous thing to do. People's lives were in danger, property was destroyed and we were very fortunate that there were not fatalities."

When questioned, the three suspects said it was "just horseplay and stupid fun," McMinn County Lt. Eric Allman said.

In connection with the overpass incidents, each of the three was charged with three counts of reckless endangerment, two counts of felony vandalism and one count of criminal conspiracy to commit reckless homicide, reports show.

Mulkey also was charged with 18 counts of attempted reckless homicide. Those charges stem from the incident in which a fan motor was thrown from the County Road 130 overpass and struck a charter bus carrying a group of Lee University students, injuring the driver, Guy said. All three men were involved but Mulkey "bears more responsibility," he said.

"This type of crime borders on terrorism," Guy said. "And we simply will not tolerate such crimes."

Each man also has charges of theft over $60,000 pending in Bradley County in connection with the airport vandalism, sheriff's spokesman Bob Gault said.

More than $100,000 in damage was done to the site in November when vandals commandeered a track hoe and went on a destructive joyride, wrecking several other pieces of equipment, Gault said.

But another vandalism investigation already was under way when the Cleveland airport was damaged, police said.

Athens police started an investigation in early November when a report on stolen construction equipment was filed, Athens Police Department Detective Sgt. Heith Willis said. Because the crime was similar to reports of vandalism at the Cleveland airport, Athens police teamed up with the Bradley County Sheriff's Office, he said.

"Police thought they were related," Willis said.

One overpass incident occurred Nov. 16 when a mailbox thrown from the County Road 326 overpass struck the windshield of a tractor-trailer on Interstate 75, injuring the driver, police reports show. The Lee University bus was struck on Nov. 27, records show.

Another truck was struck by a mailbox in December, and all three suspects confessed to a fourth incident in which nothing was hit, Guy said.

Cleveland Mayor Tom Rowland raised $13,500 as a reward for people to come forward with tips on the incidents.

It wasn't until tips started coming in and informants in the undercover investigation began to talk that sheriff's investigators and police linked the overpass and vandalism crimes, Willis said.

Arraignments in the overpass incidents are scheduled Tuesday in McMinn County General Sessions Court, clerk officials said. Afterward, the men will be charged in Bradley County and in Athens on theft charges in connection with the vandalism, authorities said.

All three men were living with their parents when the arrests were made, and the parents were shocked when they found out, Guy said.

"The parents came down and spoke with us [Thursday morning]." he said. "They were just upset their family was involved."

Contact staff writer Joy Lukachick at jlukachick@timesfreepress.com or 423-757-6659. Follow her on Twitter at twitter.com/jlukachick.