Fullerton, Calif. ? Detective Mike Kendrick began photographing the body of a little girl on an emergency room table for an investigation of a drowning.

Then, through the lens, he saw her chest move. Just spasms, he thought. Then he saw it move again. And again.

“Am I seeing things? Does she look like she’s breathing?” Kendrick asked his partner.

Less than an hour earlier, Kendrick had broken the news to the girl’s mother that she had been pronounced dead by doctors. Minutes earlier, he stood by as the mother said goodbye to her daughter.

But 20-month-old Mackayala Jespersen was indeed alive. On Friday, she was in serious condition at Children’s Hospital of Orange County, where she was transferred after being revived.

Her case has baffled hospital and emergency workers. They had struggled to revive her with CPR, breathing tubes, a heated blanket. How could they have missed the fact that the toddler was alive?

The Medical Board of California has launched an inquiry into whether physician error played a role, although the state Department of Health Services already has found that Anaheim Memorial Hospital followed proper protocol.

The girl’s family declined to be interviewed.

On Friday, the girl was breathing without a ventilator but was not fully alert. She was moving her eyes and her body somewhat, hospital spokeswoman Denise Almazan said. Earlier in the week, one of the girl’s doctors said brain scans showed no serious brain damage.

Detective Mike Kendrick, left, and his partner, Detective Brent Rebert, of the Fullerton Police Department, were photographing the body of 20-month-old Mackayala Jespersen for an investigation of a Nov. 7 drowning when they discovered the child was breathing.

Mackayala slipped out the back door of her family’s home in Fullerton, about 30 miles south of Los Angeles, on Nov. 7. A family member found the girl floating face-down in the 52-degree water of the swimming pool shortly after 9 a.m., according to police reports and emergency workers.

At 10:45 a.m. — 39 minutes after Mackayala had been pronounced dead — her chest appeared to spasm.

“It looks like she’s breathing,” Kendrick told his partner. “Go and get somebody.”

Rebert returned with a nurse, who put a stethoscope to the girl’s chest. Doctors raced in. Machines were turned back on. Mackayala had a pulse. The two police officers shook their heads in disbelief.

Kendrick had the job of telling Mackayala’s mother that her daughter was alive. This time, she fell to her knees and thanked God.