PLAISTOW — Four coworkers returned from an out-of-state convention and were poisoned, three of them fatally, by carbon monoxide before they could return to work.
Fire officials yesterday confirmed the identities of the three people who were found dead Tuesday in a home at 5 Center Circle.
Kirk Walsh, 32, MaryAnn Comparato, 47, and John Adams, 28, were found dead in Walsh’s home.
A fourth victim, Keith Small, remains hospitalized at Massachusetts General Hospital. Plaistow fire Chief John McArdle said Wednesday Small was being treated in a hyperbaric chamber. A hospital spokeswoman said yesterday she could not release any information about Small’s condition.
The four victims worked at ACN, a North Carolina-based marketing company.
“All four people were on my ACN team and very active in our group,” said Frank Licata of Andover, Mass.
He said the four were staying at Walsh’s home after returning from a convention in Charlotte, N.C.
Walsh would have been 33 yesterday. He was the company’s New England regional director.
“He quit his job as plastics engineer,” Licata said. “He went to UMass Lowell and, in his late 20s, he quit his job to work at ACN.”
The victims had returned from the convention Sunday night, according to Licata.
He said he didn’t attend the convention. He said he grew increasingly concerned Monday when none of his colleagues answered their cellphones.
“It seems like they came back (from Charlotte) Sunday night and were at Walsh’s house and never woke up,” Licata said yesterday.
Police and firefighters went to the home at about 11:30 a.m. Tuesday in response to a request for a well-being check.
Walsh, Adams and Comparato were found dead. Small was alive, but unconscious. All four appeared to have been sleeping when they were overcome by the deadly gas.
Plaistow fire Chief John McArdle said they measured CO at 400 parts per million. Detectors typically will sound an alarm at 35 to 50 parts per million, he said.
There was a CO detector in the house, McArdle said, but the batteries had been removed, rendering it inoperable.
Yesterday, State Fire Marshal J. William Degnan said the investigation was continuing.
Investigators believe the propane heating system was the source of the carbon monoxide, Degnan said. A furnace vent had been disconnected, McArdle said earlier.
The investigation into the furnace and its installation continues.
That investigation will last a few more days, Degnan said.
“We’re looking at the furnace in detail,” he said. “That will include going through complete installation and set up of the furnace. There were several interviews done to try to narrow down details of the installation and if there were other people had been in the home and affected by it.”
The investigation is being conducted by Degnan, McArdle and Plaistow police Chief Stephen Savage.
Town records say that Walsh, who was a UMass-Lowell graduate, owned the home.
Licata said Walsh gave up his engineering job because he was able to make more money. “His whole reason for doing ACN, he was trying to retire his parents because they spent their retirement on his and his sister’s education,” Licata said.
Walsh was the son of Methuen building inspector Gene Walsh, according to Licata.
Licata said when he joined the company a little more than a year ago, Walsh trained him. Licata said Walsh led weekly training sessions for the team on Saturdays in Woburn.
Comparato was the mother of two children, a son and daughter, both of whom attend Andover public schools.
She had worked as a special education classroom aide in Andover’s elementary schools for a couple of years, but left that position about six months ago, according to the Andover School District.
Adams was from the Plaistow area, according to one of his colleagues, Gil Pementel.
Small’s Facebook page said he was living in Groveland, but was from Lynn. He was a 1970 graduate of Lynn Trade School.
On Facebook, many expressed their condolences to the victims.
“I was shocked to find out it was you that was taken so soon,” Samantha Barnard wrote on Walsh’s page. “May you rest easy my friend.”
Peggy Nolan wrote on Comparato’s page.
“My heart is heavy,” she said. “Rest in peace. My love and prayers to your family and friends.”
Plaistow Town Manager Sean Fitzgerald said the town was still grieving.
“Lots of folks in town are heartbroken,” he said. “Any loss is tragic, but it is especially troubling when you know that it could have been prevented through some working detectors.”
Staff writers Douglas Moser and Judy Wakefield contributed to this report.