SAN JOSE (CBS SF) - An elderly woman was in critical condition and another injured from a two-alarm residential fire near Penitencia Creek County Park in San Jose Friday morning, according to the fire department.

The fire was reported around 8:40 a.m. at a home in the 2000 block of Commodore Drive.

Battalion Fire Chief Jose Guerrero said fire crews arrived to large flames and heavy smoke coming from the back of the house and were told a grandmother in her 70s was trapped inside.

"They were on their hands and knees throughout the house searching" as heavy pieces of the home's red-tiled roof fell to the ground, said Guerrero.

Firefighters eventually found the woman unconscious in a back bedroom, said Guerrero. She was hospitalized in critical condition, he said.

One other person suffered smoke inhalation. Two other people inside the house at the time escaped unhurt, according to the fire department.

The fire began in the home's kitchen and dining area and spread to a back patio and through the roof, he said.

Guerrero said the cause of the fire was apparently not cooking-related but has not yet been determined.

The battalion chief said he did not know whether the home had working smoke detectors. "If you have a working smoke detector, it will alert you to the fire when it's still small and it will not get to this condition," he said.

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