Hundreds of investigators combed an area around a collapsed building near the Pattridge Park open space in Arvada Wednesday night after a body was discovered, about 11 miles south of where Jessica Ridgeway’s backpack was found.

At a hastily called press conference, Westminster police spokesman Trevor Materasso said “we are unable to make a connection to the disappearance of Jessica Ridgeway.”

Since Saturday, more than 1,000 citizen and law enforcement searchers have combed open spaces around Jessica’s Westminster home and near where the backpack was found in the Rock Creek neighborhood.

Wednesday afternoon, federal and police investigators swarmed a grassy area north of West 82nd Avenue and east of the BFI landfill. They were aided by lights and using a fire truck with its ladder extended to get a better view. Their work was focused near a building that appears to be a remnant of an old mining operation.

The Colorado Department of Transportation closed Colorado 93 in both directions at Leyden Gulch.

Materasso called the area a crime scene and said it had been secured to allow investigators to work through the night. He gave no more details and declined to answer questions.

Police will hold another briefing at 6:30 a.m.

Earlier in the day, police said they had concluded the missing 10-year-old is likely the victim of an abduction after ruling out her parents as suspects.

“We’re confident the parents are not involved in the disappearance of Jessica Ridgeway,” Materasso said at an afternoon news briefing. “The focus shifts to an unknown suspect because we think she was abducted.”

Wednesday night, Jessica Ridgeway’s home was quiet. No one answered the door. A neighbor said he had seen Jessica’s father, Jeremiah Bryant, run out of the home at about 6:45 p.m.

Materasso said during the afternoon briefing that investigators have no specific leads or suspects, although he acknowledged that detectives have been interviewing registered sex offenders in the area.

“Sex offenders have been a focus of ours as standard procedure,” he said.

In September, Faith Christian Academy, 12189 W. 64th Ave. and an Arvada-area soccer program, separately warned parents and guardians that a stranger had approached students in two reported incidents, one at Fitzmorris Elementary school and another near Quaker Acres park. The man offered them candy and asked them to get in his car. Police reports were filed. A sketch of the suspect was made.

Jessica last was seen leaving her home on North Moore Street in Westminster around 8:30 a.m. Friday. She was to meet with classmates at nearby Chelsea Park to walk to Witt Elementary, but she never arrived at school that morning.

Her mother, Sarah Ridgeway, a night-shift worker, slept during the day and awoke to find a message that her daughter never made it to school and reported her missing around 4:30 p.m. on Friday.

Additional people have been brought on board to handle the large number of tips generated in the case “from across the country” — more than 650 had been received by phone and e-mail, Materasso said.

Kieran Nicholson: 303-954-1822, knicholson@denverpost.com or twtter.com/kierannicholson

Staff writers Tom McGhee and Nick Groke contributed to this report.