Workers cause Freon leak at Des Plaines city hall

Des Plaines evacuated its city hall about 11:12 a.m. today due to a Freon leak in the basement, Fire Chief Alan Wax said.

Work has been under way recently to upgrade the building's heating and air conditioning system, and workers somehow let the gas escape from a tank, Wax said. The fire alarm was used to evacuate people from the building.

The leak was capped but pockets of the gas that remain in the building were still being ventilated as of 12:15 p.m., he said.

Crowds of city workers were gathered around the building, but it appeared likely employees would be back in the building by 1 p.m.