Dublin, CA – By Simon Read, Inside Bay Area

A propane explosion destroyed a cafeteria under construction at Fallon School on Wednesday night, blasting a hole in the structure’s roof and blowing a set of double steel doors into the school’s parking lot.

Alameda County Fire Department Capt. Randy Moore called the amount of damage done “amazing” and estimated that repair costs will be somewhere in the millions.

Two school custodians still on campus reported the blast at the newly built school, 3601 Kohnen Way, about 10:20 p.m., Moore said. Firefighters arrived on the scene within minutes to find smoke and flames billowing through the roof.

Additional units were summoned at 10:27 p.m., Moore said, bringing the total number of firefighters battling the blaze to 35. Two trucks, six engines and one ambulance also were involved.

No one was injured, Moore said.

Firefighters extinguished the blaze about midnight, Moore said. A group of reserve firefighters remained at the school overnight to ensure the fire didn’t reignite.

“The building that burned was still under construction,” Moore said. “It was attached to the school’s multipurpose room.”

The building had several propane heaters that were left on overnight, Moore said.

“One of them began leaking,” he said. “The level of propane reached a sufficient level to spark, resulting in the explosion.”

Moore said the force of the blast ripped several of the building’s support beams from their anchorings and tossed aside a massive air-conditioning unit on the building’s roof.

“It threw this unit across the roof like it was nothing,” Moore said, adding other school buildings escaped damage.

“The fire was confined to the kitchen area,” said Sandy Hare, assistant superintendent of Dublin schools. “The whole building is cinder block, so the fire did not mutate to other parts of the building.”

Hare said it will be several weeks before officials arrive at a damage estimate, but she said she believes “the damage could have been a lot worse.”

“We were looking at the damage last night with a flashlight,” she said. “It’s hard to say how much it will be.”

The heaters in the building had been left on to maintain a constant temperature for some newly installed building materials, Hare said, adding the school board’s president called the school superintendent Wednesday night after receiving four calls in 60 seconds from residents near the campus.

“Somebody obviously heard something,” Hare said. He thanked firefighters for their efforts. “We had a lot of great crews out. You’ll hear no complaints.”