A CalFire captain directs his team to safety while protecting a home from the Bluecut Fire Wednesday Aug. 17, 2016 in Cajon Pass, Calif. A wildfire with a ferocity never seen by veteran California firefighters raced up and down canyon hillsides Wednesday, instantly incinerating homes and forcing thousands of people to flee, some running for their lives just ahead of the flames. (James Quigg/The Daily Press via AP)
A CalFire captain directs his team to safety while protecting a home from the Bluecut Fire Wednesday Aug. 17, 2016 in Cajon Pass, Calif. A wildfire with a ferocity never seen by veteran California firefighters raced up and down canyon hillsides Wednesday, instantly incinerating homes and forcing thousands of people to flee, some running for their lives just ahead of the flames. (James Quigg/The Daily Press via AP) Credit: JAMES QUIGG

A wildfire with a ferocity never seen before by veteran California firefighters raced up and down canyon hillsides, instantly engulfing homes and forcing thousands of people to flee, some running for their lives just ahead of the flames.

By Wednesday, a day after it ignited in brush left tinder-dry by years of drought, the blaze had spread across nearly 47 square miles and was raging completely out of control. The flames advanced despite the efforts of 1,300 firefighters.

Authorities could not immediately say how many homes had been destroyed, but they warned that the number will be large.

โ€œThere will be a lot of families that come home to nothing,โ€ San Bernardino County Fire Chief Mark Hartwig said after flying over a fire scene he described as โ€œdevastating.โ€

โ€œIt hit hard. It hit fast. It hit with an intensity that we hadnโ€™t seen before,โ€ he said.

No deaths were reported, but cadaver dogs were searching the ruins for anyone who was overrun by the flames.

In 40 years of fighting fires, Incident Commander Mike Wakoski said, he had never seen conditions as extreme as those in Cajon Pass, where the fire broke out Tuesday morning.

Residents like Vi Delgado and her daughter April Christy, who had been through a major brushfire years before, said they had never seen anything like it either.

โ€œNo joke, we were literally being chased by the fire,โ€ a tearful April Christy said in a voice choked with emotion as she and her mother sat in their minivan in an evacuation center parking lot in Fontana. They did not go inside because their dogs, three Chihuahuas and a mixed-breed mutt, were not allowed.

โ€œYouโ€™ve got flames on the side of you. Youโ€™ve got flames behind you,โ€ Christy said, describing a harrowing race down a mountain road. She was led by a sheriffโ€™s patrol car in front while a California Highway Patrol vehicle trailed behind and a truck filled with firefighters battled flames alongside her.

She and her mother, onsite caretakers at the Angels and Paws animal rescue shelter in Devore Heights, said it was only moments after they smelled smoke that flames exploded all around them. They grabbed their pets and tried to rescue nine other shelter dogs and three cats, but a sheriffโ€™s deputy told them there was no time.

โ€œYou wonโ€™t make it. Save yourself. Take your truck and leave,โ€ Delgado said the deputy shouted at her, adding that he and others would try to rescue the animals. She learned later that authorities did save the animals, but officials could not tell her if her home survived.

More than 34,000 homes and some 82,000 people were under evacuation warnings as firefighters concentrated their efforts on saving homes in the mountain communities of Lytle Creek, Wrightwood and Phelan. They implored residents not to think twice if told to leave.

โ€œThis is not the time to mess around,โ€ said Battalion Chief Mark Peebles of the San Bernardino County Fire Department.

Six firefighters were briefly trapped by flames during the fireโ€™s early hours, when occupants of a home refused to leave and the crew stayed to protect them.

โ€œThis moved so fast,โ€ said Darren Dalton, 51, who along with his wife and son had to get out of his house in Wrightwood.