VALLEJO (CBS SF) — Two staff members were injured at Vallejo High School after a maintenance worker re-lighting the pilot caused an explosion. According to officials, the school’s gas lines had been turned off since they had ruptured during the August 24th Napa earthquake.

The explosion reportedly occurred around 8:30 a.m. in a room near the rear entrance of the school that was described as a “mostly abandoned room” that is occasionally used as a photo lab. PG&E spokeswoman Brittany McKannay said the Vallejo Fire Department called PG&E between 8 and 8:30 a.m. to shut off the gas line to the school, fire officials said.

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There were no students present near the room at the time of the explosion and none were injured.

The maintenance worker sustained “serious” burns and injuries according to the school superintendent and was sent to Kaiser Hospital along with another employee who was injured to a lesser degree in the blast.

There had been no natural gas service to the school since the Napa earthquake, but in the last couple of days the school had started to get the gas flowing.

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PG&E shut off the gas and electricity to the school after the explosion. Power has since been restored. PG&E has given the all clear, but the gas will remain off in the meantime.

School has since resumed for the day after the brief evacuation. However, some parents, who were upset, have taken their children from school as a precautionary measure. Many of them expressed frustration and said the school doesn’t inform them adequately when a situation like this arises.