After this week's discovery of a Minnesota family fatally poisoned by carbon monoxide gas, authorities have renewed pleas for families to install and maintain working carbon monoxide detectors.

The tragedy of seven Moorhead residents dying in their home highlights the threat from the colorless, odorless gas, which kills 400 people each year nationwide. In Minnesota, carbon monoxide kills about 14 people and sends 300 to emergency rooms each year, according to the state Department of Health.

Also this week, a Shakopee family called 911 on Tuesday after three in the house started feeling ill; all eight were conscious and alert but were transported to the hospital and found to have mid-range levels of carbon monoxide in their blood, according to city officials. No carbon monoxide detectors were found in the home.

Two residents of an apartment building in Fargo were hospitalized this week for symptoms of carbon monoxide poisoning, according to Fargo police.

At a news conference Wednesday, Moorhead Fire Chief Jeff Wallin said people should have working detectors within 10 feet of any sleeping space and replace the devices every five to seven years.

"The longer that you have a cold-weather season and have heating appliances, the more opportunities there are for carbon monoxide poisonings due to malfunctions," he said.

Wallin's statements came after Moorhead Police Chief Shannon Monroe announced the cause of death was lethal levels of carbon monoxide for the residents of the duplex on the city's south side.

The victims, who ranged in age from 5 to 37, were Belin Hernandez and Marleny Pinto, their children Breylin, Mike and Marbely, as well as Belin's brother Eldor Hernandez Castillo and the couple's niece, Mariela Guzman Pinto. Thefamily moved to Moorhead from Honduras less than a decade ago.

Capt. Deric Swenson of the Moorhead Police Department said Thursday that relatives of the Hernandez family contacted police Saturday evening after finding family members unresponsive. Authorities have said they've found nothing to indicate criminal activity.

"This case has been followed by a lot of people that are concerned and are sympathetic and grieving," Swenson said. "It's a major shock and a major tragedy in our community."

The origin of the Hernandez family's poisoning has yet to be determined, but investigators found two possible sources — a furnace and vehicle in the garage — and additional blood tests are underway. Detectives found a carbon monoxide detector in a cabinet detached from the wall and with a battery removed; the sensors mounted in the home were smoke-only detection devices.

"One key point that has come out today is — if replacing a combination smoke detector and carbon monoxide detector, it's important to also check to make sure you're replacing it with a similar device that can provide both levels of protection," Wallin said.

In Moorhead, the city of about 43,000 on the Minnesota border near Fargo, the Fire Department responds to about 59 carbon monoxide calls per year, Wallin said. About a quarter of those detect gas in the home.

State law requires the owner of multifamily dwellings to provide and install carbon monoxide detectors; it is the tenant's responsibility to keep the devices in good repair.

Detectors are inexpensive but many people, including native Minnesotans, are still unaware of their necessity, said Sheletta Brundidge, a Minnesota podcaster who lost five family members to carbon monoxide poisoning during Hurricane Laura in Louisiana last year.

Brundidge's family used a generator in their garage to keep it from getting stolen but kept a door open for ventilation. Strong winds blew the door shut and fumes went into the home, she said.

"It wiped out two generations of my family overnight," she said Thursday.

It became her mission to educate people and get detectors in the homes of people who can't afford them — a complaint she often hears.

"We've got these First Alert detectors in my house. As crazy as this sounds, I called the 1-800 number," she said. Brundidge asked for 100 detectors and distributed them to people who requested them via her website. For her efforts, she received the 2021 fire safety education award from the Minnesota State Fire Chiefs Association.

"When I saw what happened in Moorhead, immediately I called First Alert and was like, I need 100 detectors," she said. "I have 70 requests so far."

Brundidge plans to mail the detectors to the Moorhead-area residents over the coming days.

"The amazing thing is people send me notes that say, 'I didn't even know these existed' or 'I didn't know that I needed one,' and these are Minnesotans who have lived here all their lives," she said.