(KMOV) -- More than 100 volunteers returned to Watson, Ill., Monday to continue the search for a 7-year-old girl who had been reported missing from her home over the weekend.
Willow Long was reported missing from her home in Effingham, Ill., after her mother woke up around 10 a.m. Sunday and noticed she was not there.
Within hours of her disappearance, a team of 500 volunteers and emergency responders began combing a 20-square-mile area looking for the little girl.
After more than 36 hours, Willow's grandfather, Dale DeRyke told News 4, "I'm scared. Not knowing is the hardest part."
The search team covered eight miles on the ground Sunday and finished the other 12 miles Monday afternoon. Several air units flew over the heavily-wooded and farm area Sunday night.
"We went down the highway cut through a guys yard, searched his whole fenced area, searched his back yard and searched his barn," said volunteer Bonnie Fender.
Monday night an Illinois State Police airplane with an infrared camera was schedule to fly over fields and wooded areas surrounding the small town of Watson, where Long lives with her family. Authorities are hoping the infrared camera will give them some clues to help narrow the search.
After the fly-over, trained first responders resumed the search through the night until volunteers return in the morning. Many volunteers are parents who are thinking of their own children. Jeanette Scribner told News 4, "It's someone else's child out here lost and I just want her to be home safe."
During the initial search, someone reported seeing footprints close to a pond near the child’s home. However, Effingham County Sheriff’s officials confirm a dive team searched the pond and did not find anything.
While one police official said it is “unclear what lead” to the girl’s disappearance, foul play is not expected.
Police said the girl’s mother saw her early Sunday morning and the mother went back to sleep. She noticed she was gone after waking up.
Police said Long is 4 feet tall and weighs 40 pounds. She has shoulder-length red hair and wears glasses but didn't take them with her. Willow's mother, Cierra DeRyke, wasn't sure what Willow was wearing Sunday morning when she disappeared.
Watson’s population is 750. It is less than 10 miles south of Effingham.