The Santa Clara County Fire Department evacuated Union Presbyterian Church in Los Altos Dec. 12 after reports of a natural-gas leak. Santa Clara County Fire Chief Kenneth Kehmna said responders immediately evacuated the church campus, left, which includes a private preschool and elementary school. PG&E crews on the scene isolated the source of the leak to a kitchen stove and capped it. Some of the schoolchildren experienced headaches and nausea as a result of the leak. Four students were taken by ambulance to a local hospital as a “purely precautionary” measure.