According to a July 7 report in SFGate, the online version of the San Francisco Chronicle, a  licensed California contractor is facing up to three years in prison on manslaughter charges brought against him in the carbon-monoxide deaths of two men in Truckee, Ca. County prosecutors say the contractor, Kurt Schoemig, is responsible for cutting "two pipes" (likely the intake and exhaust vents) on a sealed-combustion furnace without turning off the gas feed or otherwise shutting down and disabling the furnace. According to the news report, Schoemig's crew cut the vents to make room for a new door to a garage, which was being built to house the owner's golf cart. The cut vents, prosecutors say, caused the deaths of the owner and a friend within minutes of coming home. The owner used a cellphone app to turn on the cabin's heat remotely, so the furnace had been running for a couple hours, filling the closed-up cabin with exhaust gasses before the occupants arrived.

In March, prosecutors filed manslaughter charges against Schoemig, 41, saying he was criminally liable for leaving a hazard behind and doing the work without a permit. Prosecutors assert that if the work had been permitted, it would have been "tested," and problems averted. After Schoemig was charged, investigators found a 6-inch-thick nest - presumably made by a bird or rodent - in the intake vent. The nest was reportedly between the cut end of the vent and the furnace. The defense team argues that this nest limited the intake of air into the furnace, causing incomplete combustion, which in turn led to the cabin filling with carbon monoxide when the heat was turned on.

A call by JLC to the defense attorney failed to confirm the details in the SFGate article. In particular, the news article reports that investigators "believe a sensor inside the furnace - designed to shut it down when air intake is limited - malfunctioned." This detail is reported to be part of the defense team's argument, but it could work against them: Cutting the intake might have lowered the back pressure, letting enough air through the nest "filter" to allow the furnace to operate.

Either way, it's a rough defense. As the the prosecution asserts, "... had the pipe [sic] not been cut, the deaths would not have occurred."

What's perhaps most surprising is the charge of manslaughter. If the contractor cut the furnace vents without shutting down the furnace, he may be guilty of negligence, but that is not a criminal offense. To contend that he is guilty of manslaughter suggests he was more than ordinarily negligent. Does disregard for systems in a house that are not directly part of your scope of work amount to something more than ordinarily negligence?

However this case is decided, it's a wake-up call for all contractors: Ignorance and inattention in the field may be a crime. Tell us what you think.