The evacuation of the headquarters of an Essex council was caused by carbon monoxide fumes, probably from a faulty boiler, it has been revealed.
On Friday afternoon, Southend's Civic Centre was evacuated after a man was overcome by fumes.
Police and fire officers noticed raised levels of the gas - thought to have come from a boiler.
About 15 council staff were treated for symptoms of dry, irritated mouths and throats, and stinging eyes.
Two weddings that were due to take place at the Civic Centre on Saturday will now take place at Southend Museum.