Firefighters extinguished a serious blaze at one of Britain's largest gas terminals following an explosion in a wastewater treatment plant, fire department officials said on Thursday. Several fire trucks dealt with a "very large-scale incident" at the Bacton gas terminal in Norfolk, a county east of London, said Incident Commander Richard Herrell of Norfolk Fire Service. The cause of the blaze is unknown and a full investigation has been launched. "Everyone is safe and well. It has run like clockwork. We have a well-rehearsed plan between the emergency services and this has been shown to work," Herrell said.