ASPEN, Colo. (AP) – Someone might have altered a boiler after Pitkin County officials issued a permit for an Aspen-area home where a Denver family of four died from carbon monoxide poisoning, lawyers for the county argued in a new motion in a civil lawsuit.

According to the Aspen Daily News, the motion in Denver federal court is the latest claim in the lawsuit over the 2008 deaths of Caroline Lofgren, her husband, Parker, and their two children, Owen and Sophie.

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The family was staying in the house after winning a church auction for a getaway in Aspen over Thanksgiving weekend. Investigators said a disconnected exhaust pipe leaked the odorless gas into the house.

Relatives filed a lawsuit in August 2010, alleging gross incompetence by companies that worked on the house and Pitkin County building inspectors.

Since then, attorneys for the defendants and for the family have made a series of claims and rebuttals in court motions. A hearing in the case is scheduled for Tuesday in federal court in Denver.

In their new motion seeking to have the lawsuit dismissed, attorneys defending building inspectors argued that they never saw the results of the possible alteration to the system.

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The defendants’ attorneys said that the boiler functioned without incident for two years before the family’s deaths and that there were no obvious risks of possible carbon monoxide poisoning.

“The two-year time period is critical,” the motion said. “The state of the mechanical room on the night of the Lofgrens’ death — when pipes were clearly disconnected from the boiler and the risk was correspondingly obvious — is not the issue. It is the state of the room two years before, when inspections were performed, that matters.”

The lawsuit is separate from a criminal case against a former building inspector and the owner of a plumbing and heating company. They have pleaded not guilty to felony charges of criminally negligent homicide.

A second inspector was charged with reckless endangerment but that was dropped because the statute of limitations had run out.

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