SOME 16,000 households in Tai Po were without gas for the second day in a row yesterday due to a burst water main in Ting Kok Road. Hong Kong and China Gas public relations manager Ally Ho Siu-wa said the company hoped supply would be restored by late yesterday. ''It's the first time such a great number of gas mains have been flooded.'' ''We are pumping the water and oxygen out of the gas pipes and we have put out notices to inform our customers of the progress.'' ''We hope to restore supply fully but it depends how quickly our staff can visit users to check on cooking stoves, making sure it is safe to use them again,'' she said.