Inspectors found on Saturday a pocket of underground gas from the leak that posed more problems. Kansas Gas Service officials ordered the evacuation of Cargill Salt Co. after hand-held monitors detected increasing levels of gas, said Ross VanderHamm, deputy city manager.
More than a dozen workers were evacuated, but no one at the company became ill, authorities said.
The leak was blamed for blasts that sparked devastating fires since Wednesday one that killed one man at a mobile home park and forced hundreds of evacuations and another that destroyed two downtown businesses. One woman remains hospitalized.
The leak is coming from a pipe that removes gas from a cavernous area seven miles northwest of the city and some 550 feet below the surface, said Conrad Koehler, Kansas Gas spokesman.
While overnight temperatures dipped into the single digits, crews tried to seal the leak and transfer gas from the problem cavern to nearby storage areas.
"Certainly there are some risks, but we are using people used to doing this," said Larry Fischer, Kansas Gas vice president for operations.
A fire downtown continued to burn Saturday, fed by one of at least nine lingering plumes of gas. The eight others were clustered in a residential area. At times the geysers had spewed up to 30 feet above ground, pushed by the gas pressure, but by Saturday they were running about 3 feet.
Officials said all the gas came to the surface through old wells that had been capped and forgotten as the city was built around and above them.
Workers on Saturday were completing a series of wells designed to relieve the underground pressure and further reduce the geysers.