THE China Light and Power Company pleaded not guilty yesterday in Tuen Mun Court to failing to provide and maintain a safe system of work at its Castle Peak power plant. The offence relates to an explosion which killed two engineers. The summons was issued in February by the Labour Department following the blast which killed Wong Kwong-yu, 38, and Yip Ka-pui, 40, last August. The prosecution alleges that on August 28 last year, the defendant failed to provide and maintain a hydrogen generation plant and systems of work that were, so far as were reasonably practicable, safe and without risks to the health of all persons employed there. The maximum penalty for the offence is a $30,000 fine. Magistrate Richard Day set the trial date for October 18.