Updated

Eight inmates broke out of jail in their underwear early Tuesday by climbing through an air duct to the roof and going over the side on a rope made out of their tied-together uniforms.

One of the inmates was quickly captured. About 50 deputies searched for the seven others, who were being held on charges as serious as attempted murder (search).

Sheriff Wayne Anderson said that while the inmates had carefully worked out their escape, they apparently did not plan for what do once outside in the 30-degree weather.

"They were seen across town in their underwear," Anderson said. "They didn't have anyone on the outside waiting for them, but I'm sure they've got clothes now."

The inmates stole a pickup truck and drove it through a fence to get away, then abandoned it, authorities said. Anderson said it wasn't known if the fugitives were now armed but they should be considered dangerous.

Sullivan County Jail (search) officials discovered the inmates missing before daybreak. The inmates fled from a section of the jail built in 2000.

"Hindsight is always 20-20," Anderson said. "We've been thinking about new security measures. We're going to fix it and add more measures on top of that."

Sheriff's deputies captured James Reynolds, who was being held on charges of aggravated robbery and aggravated assault. Details of his capture were not immediately released.

Blountville is about 100 miles northeast of Knoxville (search).