Updated

While parents grieve the death of two children buried under a wall of falling dirt, police are investigating possible charges against the father who was working in the two-story-deep hole when it collapsed.

Jordan Arwood, 31, of Stanley, was operating a backhoe Sunday night in the pit when the walls caved in on the children. The bodies of the two young cousins, 6-year-old Chloe Jade Arwood and 7-year-old James Levi Caldwell, were dug out Monday morning.

Arwood was the girl's father; his parents, Nancy and Ken Caldwell, had adopted the boy. Arwood lived next to his parents and the pit was on his property, Lincoln County Sheriff's Office Detective Lt. Tim Johnson said.

Johnson said investigators were interviewing family members and neighbors about the case. When they finished, they planned to present their findings to the district attorney's office.

The detective was philosophical about whether the father could be punished criminally.

"You can't punish anyone worse than that," said Johnson about Arwood's loss.

What's puzzling is why Arwood was digging the hole.

Investigators described the pit as 20 feet by 20 feet with a sloped entrance leading down to the 24-foot bottom. The children were at the bottom of the pit retrieving a child-sized pickaxe when the walls fell in on them. No permits had been issued for Arwood to dig on the site.

Johnson said people have speculated that the pit was everything from a "doomsday bunker" to an underground structure for "illegal activity," such as growing marijuana.

Sheriff's deputies on Monday removed firearms and a marijuana plant from Arwood's mobile home. Arwood is a felon who is not allowed to have guns. He was convicted in 2003 for possession of a controlled substance with intent to sell.

But it's still unclear to investigators how Arwood was planning to use the pit.

Arwood told some neighbors that it was going to be a bunker to "protect his family." Others said he told them it was going to be a basement.

But Johnson said: "There aren't many basements that are 20-by-24-by-20," he said.

"The hole itself made no sense that way it was constructed. Nothing was done the way it would be done legally."

One neighbor, Bradley Jones, a construction worker, told the Associated Press said he talked to Arwood about the hole. Jones said it had so supports to stop the sides from caving in.

"To me, it was dangerous," he said.

Dion Burleson, spokesman for the Denver Fire Department which responded to collapse, said they filled in the pit on Monday.

"It was a safety hazard," he said.

He also said everyone involved in the rescue would go through a debriefing to deal with their emotions. "A lot of people were hit hard by this."

Arwood told the AP in an email that he would respond to questions "in time."

"I cannot see through the tears to respond," he said.

Arwood's desperate voice is heard on a 911 recording released by the Lincoln County communications center on Monday.

"Please hurry ... My children are buried under tons of dirt ... They're buried under tons of clay ... It fell on top of them," he said sobbing.

Then Arwood began to pray for the children's safety.

It seemed like the entire rural community was grieving for the children on Tuesday. A prayer vigil was held Monday night at a local church. Another one was scheduled Tuesday night. Funeral services were pending.

Chelsea Jones, who babysat the children, saw them a few days ago. They were happy and running around, she recalled.

"They were full of life. I still can't believe they're gone," she said.