SAN FRANCISCO (KRON) — Gas is being restored to the PG&E customers at Geary and Parker in San Francisco after a gas line exploded and burned Thursday, causing major problems in the city.

“Our mission of being here is to collect the factual information, perishable evidence,” a representative with the National Transportation Safety Board said Thursday evening.

The National Transportation Safety Board arrived to the scene of the explosion Thursday night.

“We do have a lot of damage to the buildings but what could have been worse is that we could have suffered a lot of losses that we have in other incidents,” she said.

Four buildings were damaged in Wednesday’s blaze — some charred from the fire, other affected by water damage.

A contractor with Mastec caused the explosion while they were digging to install fiber optic cables –accidentally rupturing a PG&E gas line, causing an explosion and fire between Jordan Park neighborhood near the Inner Richmond.

Crews worked through the night to repair some of the damage caused by the fire. PG&E also restored power for about 300 customers – going door to door, relighting pilot lights.

Among the unanswered questions, there are two key concerns — did the contractors have the correct map or was the marking in the area mismarked.

“We’ll be looking at the timeline leading up to the event, we’re going to be looking into the control center, we’ll be looking at everything from work hours to training of personnel,” the NTSB representative said Thursday.

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