Couple recovering in hospital after CO leak in Plymouth

PLYMOUTH — A couple living in a condominium on Tenney Brook Road was hospitalized Wednesday, with injuries related to carbon monoxide poisoning, after a suspected hot water heater malfunctioned, leaking levels of the gas into their home described as “immediately dangerous to life and health.”

Plymouth Fire Department responded to 31 Tenney Brook Road at 4:01 a.m. on Feb. 18, after a relative of the two adults called 911.

Chief Kevin Pierce said one person called the family member in the middle of the night to say they weren’t feeling well, and the female occupant was having trouble sleeping, due to a headache. Pierce said the caller said the person wasn’t speaking clearly, and pointed to symptoms of carbon monoxide poisoning.

Pierce said the couple was immobile and unable to evacuate, and were experiencing altered mental state and nausea.

“It was basically the definition of carbon monoxide poisoning,” Pierce said.

Three firefighters came to the building, a six-unit, townhouse-style condominium. The crew, wearing self-contained breathing apparatus, measured carbon monoxide readings of more than 500 parts per million inside.

Pierce said this level was extremely high, and readings like this often result in fatalities. He said CO detectors in homes activate at 30 parts per million, and OSHA says a person can work in a room at that level for about 12 hours before showing symptoms. He said as it gets higher, it becomes toxic, and anything more than 100 ppm will cause symptoms within hours.

The condominium did have a CO detector, but it did not appear to be functioning. Pierce said crews were unable to interview the occupants due to their condition. There were smoke detectors, not activated because there was no fire or smoke.

Off-duty personnel responded with a second ambulance and engine, and Campton-Thornton Fire Rescue and Rumney Fire also assisted.

Crews quickly entered the residence, removed the couple, and provided emergency care.

Pierce said the couple was in and out of consciousness, slurring their speech and mostly unable to move. The woman was moving, but stumbling, and the man could not stand up on his own.

“I can’t believe they are alive, honestly,” Pierce said.

There were no other occupants, and the couple was taken to Speare Memorial Hospital. They were then taken by ambulance to Boston, as they could not be taken by helicopter due to weather, Pierce said.

Pierce said the patients needed to be put into a hyperbaric oxygen vessel with pure oxygen to be treated, the same system used for diving injuries. He heard Wednesday the woman was in stable condition, but didn't have a report on the man.

The entire building was evacuated, and all residents evaluated as a precaution. Pierce said there were minor readings in each of the other units, he believes due to seepage. None of the occupants of other units showed symptoms.

Being early morning, first responders knocked heavily on doors to wake up occupants to leave. Some didn’t hear it, and firefighters forced their way in, to get them out of the building. One unit was unoccupied, which firefighters confirmed was clear after forced entry.

The gas supply was shut off and secured, and firefighters cleared out the air in the building with a large ventilation fan. Air quality was monitored until the readings on the four-gas meter returned to normal, with a reading of zero ppm of carbon monoxide. Crews stayed at the scene for about two hours to make sure the building was safe for residents to re-enter.

Pierce believes the leak came from a faulty on-demand water heater, saying it basically blew exhaust straight into the unit. It doesn’t appear there was tampering or anything suspicious, but the cause is being investigated.

It is common for fire departments to respond to CO leaks, especially during the winter months, but Pierce has not seen a situation this bad in years.

He said carbon monoxide detectors should be replaced “every several years,” and recommended having heating systems maintained annually by a professional. Firefighters recommend testing detectors regularly, replacing batteries as needed, and ensuring detectors are within their recommended service life.

Early signs of CO poisoning are dizziness and nausea, and Pierce said if these symptoms occur, leave the premises immediately and call 911. Plymouth Fire officials said carbon monoxide can quickly become deadly, and early detection saves lives.

“It is odorless, tasteless, and it is impossible to detect its presence without a CO detector,” Pierce said.

The state Fire Marshal’s Office is leading the investigation. Public Information Officer Tyler Dumont said they were brought in at the request of Plymouth Fire Department.

“At this time, investigators are looking into a suspected issue with the home’s mechanical system,” Dumont said. “The investigation is ongoing.”