7 people, including 2 children, recovering from carbon monoxide poisoning in Valley Stream, police say

A detached water heater flue pipe in an "illegally subdivided" Valley Stream home likely caused the release of carbon monoxide that poisoned seven occupants, including two children, Nassau County fire officials said Monday.

All seven were hospitalized, including two women found unconscious by Valley Stream firefighters who responded to the Henrietta Street home Sunday evening, according to Nassau fire and police officials.

The victims had all recovered or were recovering, without serious injuries, Nassau police said. Updates late Monday on their conditions, or whether any or all of the victims remained hospitalized, were not immediately available.

Firefighters, under the command of Chief Anthony Capone, responded to a 911 call at 9:01 p.m. on Sunday and arrived to find two women, ages 47 and 22, unconscious inside the multi-residence house. Emergency responders also discovered elevated carbon monoxide readings of more than 800 parts per million, officials said. CO levels of more than 800 parts per million in the air can be fatal be "within minutes," according to the U.S. Environmental Protection Agency.

The World Health Organization recommends that for any eight-hour span, indoor levels of the odorless, colorless gas should be on average, below 9 parts per million, according to the New York State Department of Health.

Following an investigation, Nassau fire officials said Monday the home had been "illegally subdivided" and the source of the carbon monoxide likely resulted from a detached water heater flue pipe.

The home did not have required CO sensors, Nassau Chief Fire Marshal Michael F. Uttaro said in an emailed statement to Newsday.

Fire officials said ambulance crews from Lawrence-Cedarhurst and the Nassau police Emergency Ambulance Bureau transported the two women and five other occupants, ages 2, 10, 22, 28 and 30, to Nassau University Medical Center in East Meadow for treatment and evaluation.

Carbon monoxide gas can kill without warning, according to the Centers for Disease Control and Prevention. Many basic household items, including gas- and oil-burning furnaces, portable generators and charcoal grills produce the poisonous gas, the CDC said.

Initial exposure leads to impaired vision and coordination, headaches, dizziness, confusion, nausea and flu-like symptoms that clear once a victim has left the affected area, according to the EPA's website.

Uttaro said Valley Stream village building department inspectors who responded to the scene "vacated the illegally subdivided house due to multiple issues" including the detached water heater flue pipe, and the lack of CO detection devices as required by law.

Additional information on when or whether the residents can return to the home was not immediately available Monday.

The best form of prevention against CO poisoning, experts say, is to install a carbon monoxide detector, often coupled with a smoke alarm. Firefighters recommend that batteries in these devices be checked twice a year, in March and October, around the time clocks are adjusted for daylight saving time.

By John Valenti

john.valenti@newsday.com

John Valenti, a Newsday reporter since 1981, has been honored nationally by the Associated Press, Society of the Silurians and National Headliner Awards for investigative, enterprise and breaking news reporting, as well as column writing. He is the author of “Swee'pea,” about New York playground basketball star Lloyd Daniels. His debut crime novel, “For Nothing Is Hidden,” rooted in 1950s Long Island, was released in October 2025.