Caretaker Andrew Sepulveda Arrested After Locking Children Inside Cutler Bay Home That Caught Fire (VIDEO)

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A scary scene greeted rescue workers who entered a home in flames in Cutler Bay: two small children had been locked alone inside the house and were unable to get out when a fire started in their bedroom.

Their small bodies were found in cardiac arrest, but firefighters were able to resuscitate them.

"It seems like they were overcome with smoke, they were unconscious, unresponsive, were not breathing," Miami-Dade Fire Rescue spokesman Lt. Arnold Piedrahita told WSVN. "Fire rescue crews worked these kids feverishly and were able to regain a pulse and a blood pressure."

The children, a four-year-old boy and six-year-old girl, were airlifted to Ryder Trauma Center at Jackson Memorial Hospital and remain in serious condition.

Their caretaker, 31-year-old Andrew Richard Sepulveda, was arrested Wednesday night, charged with two counts of child neglect with great bodily harm. Sepulveda also lives at the home at 10241 Martinique Drive, and confirmed to police he was watching the kids while their mother was at work.

"The defendant admitted that he was caring for the victims when he left them alone at the residence and went to the store," reads the arrest affidavit, which says Sepulveda locked the doors to the house when he left. When he returned home to find the house engulfed in flames, he told authorities the children were inside.

“What he did, there’s absolutely no excuse,” Miami-Dade Police Det. Roy Rutland told CBSMiami. “It’s clear based on his actions he’s responsible for what occurred here today.”

The children's uncle, Moreese Moise, told reporters outside the hospital that his sister pays Sepulveda to babysit.

"I just hope they’re ok," he said.

An investigation by MDPD's Arson and Child Exploitation Units remains ongoing.