UPDATE 9/3/10 @ 5:30p.m.
PORTSMOUTH, OHIO (WSAZ) -- Help, I smell gas!

That widespread panic attack had the Portsmouth and New Boston fire departments answering calls by the dozens Thursday night. The gas company says it wasn't a gas leak, but the smell itself that got away from them.

"We smelled gas, we thought it was from our neighbor, then found out many were complaining," Alison Graf says.

Even though Columbia Gas told Graf and families in numerous neighborhoods that the nasty cabbage and rotten egg smell was not from any known gas leaks, many took no chances.

"We didn't know if it would be good or bad, so we packed up and went to my in-laws," Graf said.

The Portsmouth and New Boston fire departments responded to about 100 gas smell calls Thursday evening. Firefighters including Jeff Craig just started shutting off gas valves.

"Many people said they were getting sick and had to evacuate their home," Craig said.

Portsmouth Fire Chief Bill Raison said, "When the calls came in from a wide variety of areas, we started asking, 'What's going on?' "

Columbia Gas of Ohio says an equipment malfunction put an abnormally large amount of the chemical additive that gives odorless natural gas its nasty smell into the greater Portsmouth pipeline system.

Firefighters say their gas detection meters showed no leaks but plenty of smell.

The gas company says maybe open pilot lights or loose meter valves released the strong smell. But would some small isolated problems cause such a big two city wide stink?

"A little goes a long way," Raison said.

The Gas Company says the main smell valve is closed, the lines are clearing and the smell should soon be a faint memory. The gas company also emphasizes to never assume or take chances.

If you smell gas, call your gas company or fire department right away.

The company says the odors should go away as gas moves through the pipeline system over the next day or so.

Columbia Gas reminds customers if they have concerns about possible gas leaks in or near their homes to report the leak and a technician will come perform a safety inspection.

According to Portsmouth Fire Chief Bill Raison, Columbia Gas added too much of the ingredient that gives natural gas it's odor, causing the gas to have an especially strong smell.

Natural gas is odorless and gas companies add an ingredient that gives it a distinctive smell, making leaks easy to detect.

The chief says Columbia Gas is working to purge its lines to address the problem and that there is no danger to the public.

Fire officials in Portsmouth tell WSAZ.com that they started getting reports of the smell around noon Thursday. Firefighters have been going around to homes where the smell was reported and shutting off gas service and ventilating the buildings.

Deputy Chief, Randy Duncan says Columbia Gas has been called to investigate the source of the smell but so far haven't been able to determine its source.

Chief Duncan says 50 to 60 homes in Portsmouth have reported the smell along with several more in New Boston and across the river in South Shore, Kentucky.