Staff writer

PRINCETON-A carbon monoxide leak prompted the evacuation Wednesday night of the Gibson County Jail, as about 140 inmates were led to to confined areas outdoors by shotgun toting law enforcement officers.

More than 20 additional officers from throughout the county, as well as Indiana State Troopers, responded to the jail at about 7:15 p.m., where firefighters were trying to locate the source of the leak.

Chief Deputy George Ballard said both floors of the jail were cleared after levels of carbon monoxide were detected to be rising inside the building. Inmates were led out to the jail's outdoor recreation area and to the fenced in park across Emerson Street, where they were being guarded by armed deputies and officers. They were later placed in the still-under-construction work release detention center, next to the jail.

No one was reported affected by the gas leak.

As the source of the leak was sought, firefighters from the Princeton Fire Territory began airing out the building using fans to circulate outside air into the jail.

&#8220Levels (of carbon monoxide ) have gone down a lot," Ballard said at about 8 p.m. &#8220We don't know how or why the leak happened. Right now we're waiting on the fire department to give us the OK to go back in."

That consent was given close to midnight, as inmates began to be allowed back to their cells, according to radio traffic.

Ballard said the Sheriff's Dept. had an evacuation plan ready for such an incident, adding that if the jail was not deemed safe, a school bus was ready for transport inmates to a secondary evacuation site at the Gibson County Fairgrounds.

The evacuation was the first in the history of the current Gibson County Jail building, built in 1989.

PFT Chief Tim Speedy said firefighters normally wear masks when carbon monoxide levels reach 30 parts per million. When they arrived at the scene, however, emergency responders found pockets of air with up to 650 parts carbon dioxide per million, he added.

By 10 p.m. the levels had dropped to about 14 parts per million in most of the jail, Speedy said, but he and Harmon had agreed no one would be let back in the building until levels dropped under five.

&#8220It's slowly but surely getting done," Speedy said. &#8220We gotta keep the air moving in there and clear out one room at a time."

There are only a limited number of appliances in the building that produce carbon monoxide, and Speedy said his department was looking at a possible faulty clothes dryer as the source of the leak.

Carbon monoxide is a colorless, odorless gas that is usually hard to detect. Speedy said the only reason the leak at the jail was detected, was because a jail employee smelled the gas burning after it had likely backed up in the hose of the clothes dryer.

&#8220Luckily it was noticed before (the carbon monoxide) ever got in the jail," he said.

Gas service to the building was immediately turned off, Speedy said, but the infrastructure of the jail made it hard for air in the building to be cleared of carbon monoxide.

&#8220We're working at a disadvantage because we have a building where windows don't open," he said.

Sheriff Allen Harmon said the plan was to get the inmates back in the jail as soon as it was safe to do so.

&#8220We're waiting to see if we can alleviate the situation quickly," he said. &#8220If we get back to safe levels we'll put the inmates back in."

As of 11 p.m., the inmates were still waiting to get back inside the jail.

Dispatch and 911 service continued at the jail, despite the evacuation. Harmon said dispatchers were being rotated every 15 minutes, getting 30 minute breaks after each rotation. &#8220We have those services working like their supposed to," the sheriff said.