CONCORD (CBS SF) — A burning Concord home was rocked by a series of explosions inside its garage early Wednesday as firefighters battled to save the structure from the flames.

Contra Costa Fire Battalion Chief Pat Silva said flames and smoke were pouring out of the home’s garage when crews got on the scene in the 3700 block of Bon Homme Way around 2:40 a.m.

“We saw heavy smoke and fire coming from the garage,” said Contra Costa Fire Battalion Chief Pat Silva. “The house is an ‘L’ shape so was were a little confused at the start on where the fire was. We figured it out it was in the garage.”

But then firefighters were confronted with an added obstacle.

“Immediately we had some loud explosions from the garage,” Silva said. “I don’t know if it was ammunition or if it was propane bottles…They were really loud explosions.”

Crews mounted an aggressive attack through the front door, knocking down the fire pretty quickly, but could not save the home.

Silva said the residents could not tell firefighters what triggered the explosions. No firefighters suffered any injuries.

“An occupant of the home had minor burns to the hand,” Silva said. “She was transported to the hospital for treatment.”

The house was a complete loss. The cause was still being determined.