North Carolina authorities have suspended the license of a second heating contractor implicated in the accidental deaths of three people in two separate CO poisoning incidents in 2013 at a Boone, North Carolina, motel.

"Thomas Daniel Miller, who worked for Independence Oil and LP/Gas, agreed to a one-year suspension of his license after a conference with the State Board of Examiners of Plumbing, Heating & Fire Sprinkler Contractors," reports the Charlotte Observer (see: NC suspends contractor's license after carbon monoxide deaths at Boone hotel," by Ames Alexander).

A series of errors by a variety of tradesmen created the carbon monoxide danger, the paper reports. First, unlicensed maintenance workers replaced the Best Western motel's pool heater with a unit from another hotel. Then, according to authorities, Miller changed the fuel source for the heater from propane to natural gas in violation of the manufacturer's instructions, even though the unit was not designed for natural gas.

"The board previously suspended the license of another heating contractor – Dale Winkler of DJ's Heating Services in Boone," the paper reports. "The panel said he failed to recognize a number of problems when he was asked to check out the pool heater after the Jenkinses' deaths. Winkler is appealing in Watauga Superior Court."

The hotel manager, Damon Mallatere, has been charged with three counts of manslaughter in the case: two for the deaths of Daryl and Shirley Jenkins, who died in a room above the pool heater on April 16, 2013, and one for the death of 13-year-old Jeffery Williams, who died in the same room 53 days later.

According to the report, the vent pipe for the pool heater was also improperly installed, lacking required seals, and corroded from years of use.

Said attorney attorney Chad Poteat, who represents the Williams family: "I've rarely been part of a case where so many people failed to do the right thing."