CNN: Parents of the children trapped in a burning Mexican day care center rammed their vehicles into the building to try to free the trapped children, witnesses told CNN.

At least 38 children died when flames engulfed the building on Friday. Dozens more are in hospitals in Mexico and the United States.

Neighbors described parents arriving at the day care center completely desperate, seeing it engulfed in flames and knowing there was no way to get the children out, CNN's Thelma Gutierrez reported from the scene. They say they could hear the cries of the children and the screams of their parents.

The building had two doors, but one was padlocked shut, officials said. Windows were too high for the children to reach.

"When we went out and ran towards the nursery, teachers already had many children outside, those who could walk properly," said one man at the scene, who did not give his name.

"A pickup truck broke down the walls. The dad of one of the kids broke down one of the walls with his car driving in reverse, and that helped us a bit," he said.

One mother waited hours for information about her son, she said.

"They didn't tell us anything, nothing until like 6 p.m.," she said, when she was finally told her son was at Chavez Hospital.

"We went there and we saw that he was badly burned, 75 percent of his body was burned." The woman said they operated on the boy, but he died.

The cause of Friday's blaze remains unknown, but investigators concluded that the fire did not start inside the ABC Day Care, said Eduardo Bours, the governor of Sonora state.

As of Saturday night, at least 23 children remained hospitalized, 15 of them in critical condition, Sonora spokesman Daniel Duran told CNN. Another 10 children had been transported to other hospitals: eight to Guadalajara, one to Ciudad Obregon, and two to Sacramento, California.

A team of 29 medical experts in Hermosillo was deciding whether any more victims would be moved to the Shriners Hospital in Sacramento, or elsewhere.

In addition, six adults were injured, Duran said.

"Without a doubt this is the worst disaster we've had," Bours told CNN.

President Felipe Calderon traveled to Hermosillo on Saturday.

The president arrived with Interior Secretary Fernando Gomez Mont and Health Secretary Jose Angel Cordova to get firsthand updates from doctors and investigators, the state news agency Notimex reported.

Calderon ordered the nation's attorney general to investigate the blaze.

Most of the victims died from smoke inhalation and not burns, Bours said. But the fire was serious enough for the roof to collapse, he added.

At the time of the blaze, 142 children were inside the ABC Day Care. The day care is for children ages 2 to 4, but Bours confirmed that children even younger were among the victims.

All the children at the center had been accounted for by Saturday evening, Bours said.

A severely burned 3-year-old girl arrived Saturday at the Sacramento hospital -- where pediatric burn treatment is a specialty -- and was in critical condition, according to Dr. Tina Palmieri, assistant chief of the burn unit.

The child was burned over 80 percent of her body, the doctor told reporters. She said the hospital normally can save just over half of the children with burns that severe.

In Hermosillo, a large crowd gathered outside of the emergency entrance of the city's general hospital and many people consoled each other, video from the scene showed.

"They told me that this happened in a matter of five minutes," Hermosillo Mayor Ernesto Gandara told reporters after surveying the scene.

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