PROVIDENCE -- No foul play is suspected in the deaths of three people found inside a South Providence house yesterday, and preliminary findings are consistent with carbon monoxide poisoning, the state medical examiners office announced today.

Police believe an improperly installed heating system that leaked carbon monoxide led to the deaths. A heating system expert was inspecting the system this afternoon.

State Fire Marshal Frank Sylvester said today the house had a new gas furnace installed shortly before New Year's Day.

Overnight, investigators sealed the house and left the heater running in an attempt to gather additional evidence about a heater that may have been improperly installed.

The police and the medical examiners have not publicly identified the identities of the dead. A neighbor and a friend identified two of the occupants of the house as Sonia Maritza Flores, 46, also known as Sonia Maritza Aleman, and her son Ryan, 16, a student at the Met School. The neighbor, Jasmin Osorio, 25, said Flores’ longtime boyfriend lived with them.

The police initially treated the case as a homicide, but the department's deputy chief said last night that a preliminary autopsy found no evidence of trauma and that the deaths may have been accidental.

Deputy Police Chief Paul Kennedy said at a community meeting that their preliminary investigation indicated that a boiler had been installed improperly in the house. A preliminary investigation, the police added later, showed that its installation was faulty and that there was an elevated level of carbon monoxide present.

The decomposed bodies were discovered yesterday in the home at 345 Blackstone St. The police were called to check on them after a relative and neighbor couldn't get in touch with them.

"Positive identification of these individuals is still pending," the medical examiners' statement said this afternoon.

Officers found “a bad scene” inside the home, Kennedy said yesterday and added later that the victims had been lying there “for a period of time.”

Sylvester said he recommends carbon monoxide detectors for all houses. He said carbon monoxide detectors are as important, if not more so, than smoke detectors because you can see smoke, while a carbon monoxide leak is invisible and has no odor or taste.

The state Health Department said it wants to remind Rhode Islanders that if they suspect a carbon monoxide problem in their home, they should call their local fire department.

A crew from the gas utility National Grid was at the house this morning. Campbell said tests would be taken again today to monitor the air quality and that the boiler and other parts of the system may be removed today as evidence.

-- With reports from Journal staff writer Gregory Smith and Journal staff