Westminster Colorado Police Department/AP
10/08/2012 at 04:15 PM EDT
Searchers with horses and bloodhounds scoured open areas and neighborhoods in suburban Denver on Monday for 10-year-old Jessica Ridgeway, who disappeared on her way to school last week.
Family members started fearing the worst on Sunday when someone found Jessica's backpack in another town six miles away.
"We'd do anything in the world to get her back," the girl's great-grandmother, Donna Moss, tells KSHB-TV in Missouri
. She also says she wonders if her great-granddaughter was "led astray."
The 4-foot-10-inch-tall, 80-lb. girl disappeared at about 8:30 a.m. on Friday from Westminster, Colo., as she walked the few blocks from her home to a park where she meets friends for a 1 ½-mile walk to Witt Elementary School.
The school started calling her mother Sarah Ridgeway at 10 a.m. to say Jessica never arrived, but her mother, a night-shift worker who sleeps during the day, didn't get the message until 4:30 that afternoon. Once she did, she called authorities, who issued an Amber Alert.
The search was in full force by Saturday morning: 800 volunteers scoured the park and surrounding neighborhood while a dive team searched a lake at the park. Police called 12,000 homes, checked every registered sex offender in the area, checked car trunks and closed off neighborhoods.
Police also searched the home of her father, Jeremiah Bryant, in Independence, Mo., and ruled him out of any involvement.
To tip police, contact (303) 658-4336 or PDAmberAlert@cityofwestminster.us.