Girl, 9, Taken From Home and Slain : Crime: Child vanishes after answering apartment door in San Ysidro. Her battered body is discovered later in Chula Vista.

Every parent’s nightmare came to pass for Luis and Laura Arroyo Wednesday night, when their 9-year-old daughter disappeared after answering a knock at the front door of the family’s San Ysidro apartment and was later found slain.

Police have no witnesses to the abduction or to the killing and said they are baffled as to a motive.

The child, who was also named Laura, was in an upstairs bedroom of the family’s comfortable two-story apartment, dressed in her pajamas and watching television with her mother, when she ran downstairs about 9:10 p.m. to answer a knock at the door. When she failed to return about 10 minutes later, Luis Arroyo walked downstairs to find the door open and his daughter gone.

“I heard her say, ‘Who is it?’ when she went to the door, but I didn’t hear a reply,” Luis Arroyo said Thursday. He said he had just finished bathing his two sons when Laura ran to answer the door.

At first, the family was not concerned. Laura’s parents and her two older brothers assumed that one of the friends with whom she had been playing a short while earlier had returned to talk to her.

“But, when she didn’t came back, we went outside to look for her,” Luis Arroyo said. “I talked to some of her friends, and they said that nobody saw anything. They told me that the last time they saw her was when she walked inside the house.”

The grieving Arroyo showed the emotional toll caused by a sleepless night that saw him drive around the area, looking and calling for his missing daughter. The 32-year-old tow truck company worker’s eyes were bloodshot and teary as he told his story.

His wife and sons, Jaime, 11, and Luis, 10, were sprawled on living-room couches, emotionally drained after a night of waiting for Laura to return.

With the aid of relatives and friends, the Arroyos were able to reproduce about 300 flyers with Laura’s picture a few hours after her disappearance and passed them around the neighborhood throughout the night and early morning.

Laura’s body was discovered about 6:30 a.m. on the sidewalk of a Chula Vista industrial complex by two women reporting for work. The complex is about 5 miles from the Arroyo home.

Chula Vista Homicide Lt. Merlin Wilson said the little girl was bludgeoned about the head and stabbed repeatedly in other parts of her body.

Laura’s body was still clothed in the pink pajamas she was wearing when she disappeared, investigators said. Police said an autopsy will determine the cause of death and if she was sexually molested.

Although the girl was abducted in San Diego, Chula Vista police assumed control of the investigation because they believe the slaying occurred in their jurisdiction.

Laura’s murder was not the first time that a child had been attacked at the pleasant apartment complex in the 1500 block of Monterey Pine Drive, where the young girl lived. Two weeks ago, a 9-year-old boy who lives in the same complex and was a classmate of Laura’s at Nicoloff Elementary School was almost abducted by two women, police confirmed.

The boy’s mother, who did not want her or her son’s name publicized, told The Times that the unidentified women attempted to abduct her son as he walked home from school.

“They walked up to him and said that his mother wanted them to take him home. They grabbed him, but he pushed them away and ran home,” said the mother.

San Diego Police Detective Eduardo Medina confirmed details of the attempted abduction. Medina said the incident occurred June 3, about 2:30 p.m., in the 3000 block of Village Lane Drive. Police described the two female suspects as white and skinny with long hair.

Chula Vista detectives said they are aware of the attempted abduction but do not know if the two incidents are related.

On Wednesday, a detective, who was interviewing residents of the apartment complex, said investigators are frustrated by a lack of clues or leads.

“This one is difficult to explain. It doesn’t appear to be drug-related, and the family appears to be a normal, hard-working family. We could use any help that the public can give us,” said the detective.

Luis Arroyo said he too is at a loss to explain his daughter’s kidnaping and death. The family has lived in the complex for more than a year, and Arroyo said he did not know of anybody who might have a grudge against him or his family.

“She’s a little girl. How could she have any enemies? This is all senseless,” Arroyo said as he attempted to hold back tears.

One theory being studied by Chula Vista detectives is that Laura may have known her abductor or abductors. Investigators think this may be a possibility because the child did not scream and there were no signs of a struggle either inside or outside the doorway.

“We don’t rule out any possibility. But we don’t have any information to believe that Laura knew the person or persons who abducted her,” said Wilson, the Chula Vista detective.

San Diego police spokesman Bill Robinson said his department received a call about Laura’s disappearance at 9:40 p.m., Wednesday. Officers from the Southern Station in San Ysidro conducted a search of the area but found no trace of the missing girl, Robinson said.

Luis Arroyo said he called police minutes after his daughter’s disappearance at about 9:10 p.m. He said that a police dispatcher put him on hold for about 20 minutes before someone took his call.

Although Arroyo said he dialed the 911 emergency number, Robinson said the man probably dialed the department’s 531-2000 switchboard number instead, which could explain the lengthy delay by police in taking Arroyo’s report.

The distraught father said he learned that police had found his daughter’s body through a co-worker at J.C. Towing in Chula Vista. John Clark, an owner of the towing company, said a dispatcher who was monitoring a police scanner heard a radio call about a child’s body that was discovered on a sidewalk at 1151 Bay Blvd.

“We sent an operator to the scene with one of the flyers that Luis had printed. . . . I believe she was identified through the picture on the flyer,” said Clark.

Clark said that Arroyo has been an employee of the towing company for two years.

“Luis and his family are good people. I know his family very well from the company picnics and other functions that we have. . . . Whoever did this is a bunch of sickos. They have hurt a wonderful family,” Clark said.

Local members of the California Tow Trucks Assn. have started a fund for the Arroyos to help with burial expenses for Laura, Clark said. People wishing to contribute can call J.C. Towing at 429-1492 or 427-1492, he said.