Parker and Caroline Lofgren and their children were delighted to win a fundraising auction at their kids' school for a vacation in a $9 million Aspen, Colo., mansion.
The newly built 3,250-square-foot house had three bedrooms, three full and two half bathrooms and private river access.
It also had a faulty pipe in the heating and snow melt system, which leaked carbon monoxide and killed the family while they slept, according to investigators.
Now police are sending technicians and detectives to the house to determine whether anyone is at fault for the deaths.
Pitkin County Sheriff's Office Detective Marie Munday told ABCNews.com that the cause of the carbon monoxide appears to be a disconnect in the heating and snow melt system where the PVC piping was not glued together.
The Lofgrens decided the week before Thanksgiving to spend the holiday weekend with their two children, Owen, 10, and Sophie, 8, at a the home outside Aspen near the picturesque Independence Pass.
Their bodies were found Friday in one of the bedrooms where they had been sleeping. The grisly discovery was made by friends who had arrived at the house to spend a few days with the Lofgrens before they headed home.
The family was a close-knit group of accomplished skiers, according to Scot Wetzel, a good friend who has been acting as the family's spokesman.
"They were actually supposed to be with us for Thanksgiving," Wetzel told ABCNews.com. Instead, they headed up to the house in Aspen after winning a stay there during a fundraising auction at the children's school.
Parker Lofgren "was my best friend," Wetzel said. "We shared everything."
Ross Buchanan, a Denver-based personal injury and product liability lawyer, said that he could only speculate as to where this case will go now, but that his first look would be at whoever didn't properly glue the PVC piping together, likely a contractor.
Construction law in Colorado has its own set of liability laws, he said, and claims typically deal with property damage not human death.
"The loss of life is immeasurable," he said.
There's also a possibility, he theorized, that even the manufacturer of the faulty equipment -- maybe the glue or pipes, if it wasn't working properly -- could also be held liable.
Buchanan said he doesn't see how St. Anne's Episcopal School, which auctioned off the stay in the house, could be liable under Colorado law because it was not responsible for the house's condition.
But, he said, the owner of the property could possibly face liability under Colorado law that would likely classify the Lofgrens as "invitees." In that case, the owner of the property could be held liable for any dangerous conditions the owner knew about or should have known about.
"To me that's a very significant question in this case, whether the owner had any inkling," Buchanan said. "I'm assuming he didn't. But should he have known?"
The house is owned by Jonathan Thomas of Meyer Holding Corp. A man who answered the phone at Meyer Holding said the company was not commenting on the deaths and a call to a listing for Thomas on Popcorn Lane, down the street from the house the Lofgrens were staying at, went unanswered.
The owners had reportedly been in the house the weekend before the Lofgrens' visit and experienced no problems.