IT SEEMED as though things couldn't get much worse for Kelly and Kimberly Kongkham.

The sisters, ages 10 and 8, lived with a mentally impaired mother, who refused to send them to school. She shaved their heads, to discourage any interest from boys. She kept their rowhouse almost vacant, prompting concerned neighbors to fill it with food and furniture, for the good of the girls.

But things did get worse.

In October, three weeks after social-service workers placed the girls in a foster home, Tammy Kongkham, 35, allegedly kidnapped her daughters outside their Juniata Park school.

She fled with the children to Fort Lauderdale, Fla., where police say the trio lived "like animals" for weeks in a cave they dug under a beachfront playground, scavenging for food in trash cans, eating coconuts they found on the beach or sometimes not eating at all.

Police found the older girl last week at a Fort Lauderdale shopping mall, begging passers-by for food and money, after her mother told Kelly they had to "split up." Detectives believe the girl had been on her own about a week.

Her sister and mother remain missing, although police suspect they are still in South Florida. Investigators are concerned about Kimberly's well-being.

"We're afraid that the mom's going to go into hiding," said Detective Yvette Martinez, a spokeswoman for the Fort Lauderdale Police Department. "If she was willing to leave her 10-year-old daughter behind . . . then we don't know how much further she'll go not to get caught now."

Although Kongkham allegedly seized the girls Oct. 16, city and state police never issued a public bulletin about the abduction.

State police said the case didn't meet the criteria to issue an Amber Alert. City police didn't publicize it because the incident appeared to be a custody dispute, "the investigators didn't ask us to . . . and we didn't have a photo," Philadelphia Police Spokesman Lt. Frank Vanore said.

Vanore added that city detectives monitored area airports after learning that Tammy Kongkham might have planned to take the girls to Vietnam, her home country. They also alerted the National Crime Information Center, a database of missing-person cases, he said.

Further, Department of Human Services spokeswoman Alicia Taylor said DHS officials notified the National Center for Missing and Exploited Children and hired a private investigator to find the girls.

Kelly Kongkham might still be missing if not for a sharp-eyed Fort Lauderdale detective who, while off-duty and shopping at the city's glitzy Galleria mall on Dec. 4, spotted the girl wandering aimlessly in filthy, mismatched clothing and begging shoppers for handouts.

When the detective approached, Kelly gave a phony name, insisted she was 18 and invented a story about waiting for her parents, who she claimed were in New Jersey selling their house and would soon join her in Florida, Martinez said.

The skeptical detective took the girl to the hospital, where she finally admitted her true identity Tuesday night, Martinez said. Investigators suspect the girl initially lied because the mother had "brainwashed" her.

This week, Kelly told investigators that her mother, wearing a blond wig, had taken her and her sister from the schoolyard of Juniata Park Academy on their way into school.

School District Spokesman Vincent Thompson said it would have been their first day of school; they were registered Oct. 15 and were set to start classes the next day. He denied that the abduction happened on school grounds.

The trio took a Greyhound bus to Florida, where Tammy Kongkham took them to a playground off Highway A1A and dug out a hidden cave underneath the playset's platform, Martinez said.

The cave became the girls' cage for at least two weeks, Martinez said.

Only 2 to 3 feet tall, the hollow wasn't tall enough for the girls to stand or even sit, Martinez said.

Kelly told investigators that her mother forbade the girls from leaving, although she occasionally made outings to bring back food.

Tammy Kongkham forced the girls to relieve themselves in the cramped space rather than risk being seen by going to a public bathroom, Martinez said.

Kelly told police "she could hear the kids above her playing and laughing, while she and her sister were told to be quiet and not move," Martinez said.

"At some point, her mom told her that if the three of them stayed together, they were going to get caught," Martinez said. "So since [Kelly] was the oldest, she left her there with some coconuts and told her to hide there for a few days."

When Kelly did venture out, she regularly trekked unnoticed along the busy, tourist-packed Highway A1A, walking about three miles to the Galleria mall. Besides begging for food, she wandered the stores, even loitering at the Neiman-Marcus makeup counter for a makeover, Martinez said.

Kelly told investigators she hadn't been to school since second grade, and her sister had never been to school.

DHS social workers traveled to Florida yesterday to retrieve Kelly, who will get counseling to help cope with her ordeal, Taylor said.

Tammy Kongkham, meanwhile, is wanted for kidnapping and related offenses by the FBI and police in Philadelphia and Fort Lauderdale.

The last known sighting of Kimberly and Tammy Kongkham was at a Pompano Beach flea market, Martinez said.

"I can't even begin to imagine how Kelly feels," said Marybell Perez, the foster mother who was caring for the girls when they were snatched. "These are scars that she has to carry for the rest of her life. I always told her that no matter what, she always has God next to her and she could ask him for help, so I believe that's what kept her safe."

Under her care, the girls had put on weight and started smiling again, Perez said.

"They were blooming," she said. "I don't know what's going to happen now. This is devastating." *