AURORA, Colo. -- It is a heartbreaking story, made even worse by the fact that there are few answers as to what killed two children in Aurora last week.

"It's uneasy. You wonder what went on with all the stuff that goes on in the world today and whatever else you kind of wonder what happened. It's kind of a mystery," said Jason Gooch, a concerned neighbor.

While teddy bears and cards piled up outside the childrens' home Monday (pictured, left), questions were piling up for investigators.

7NEWS reporter Julie Hayden reported new information from the Arapahoe County coroner's office Monday. As Hayden reported, everything hinges on the final autopsy results.

Monday, a judge sealed all the information and evidence gathered on the investigation, Hayden said. It's the kind of step police and prosecutors ask for when there's evidence to seal and they anticipate filing criminal charges, according to Hayden.

Meanwhile, investigators hope the toxicology report will answer the question: What happened in the Aurora home last week?

Crime scene tape still seals the door and windows of the house.

Teddy bears and prayers have been left for Rhapsody and Robert Henderson while investigators got closer to determining who is responsible for their deaths.

Detectives searched the house Friday, and again Saturday, taking possible evidence in the case.

7NEWS has learned among other things police seized were over the counter and prescription drugs.

That's important, because investigators suspect toxic ingestion of something like those kinds of drugs may have caused the childrens' deaths, Hayden reported.

But there was no evidence that the children had tampered with or gotten into any dangerous substances on their own.

While police try to figure out the how it happened, toxicology will determine what happened.

The El Paso County sheriff's lab is testing for prescription and over the counter medicines and poisons.

Those results are expected by the end of the week.

While the exact cause of death remains a mystery. Here is what was known Monday:

The children's father says the two were not feeling well at 8 a.m. Thursday.

They went to bed. At lunchtime they ate peanut butter and jelly sandwiches, watched a little television, then went back to bed.

Between 1 and 2 p.m., their father went to work, and their mother came home.

Thursday evening, relatives dropped by and that's when the children were found dead.

The 911 call was made a 5:39 p.m. Thursday.

Autopsies were completed over the weekend, with no conclusive findings as of Monday.

Problems in the home such as carbon monoxide poisoning or a natural gas leak have also been ruled out.