Anna Faris has a lot to be thankful for — and after the Thanksgiving she and her family had last week, just being alive is at the top of that list.

The actress was celebrating at a vacation rental in Lake Tahoe, California, when guests suffered from a mystery illness that led rescuers to discover dangerous carbon monoxide levels at the location.

I’m not quite sure how to express gratitude to the north Lake Tahoe fire department- we were saved from carbon monoxide- it’s a stupidly dramatic story but I’m feeling very fortunate pic.twitter.com/zqsW77Tda0 — Anna Faris (@AnnaKFaris) November 30, 2019

“I’m not quite sure how to express gratitude to the north Lake Tahoe fire department — we were saved from carbon monoxide — it’s a stupidly dramatic story but I’m feeling very fortunate,” the “Mom” star wrote.

The 43-year-old’s message accompanied a photo of her family’s dinner, left half-eaten on the abandoned dining table.

That haunting image hints at what could have been lost, had two of the guests not gone to the hospital for what turned out to be symptoms of carbon monoxide poisoning. That’s what tipped off the first responders who rushed to the residence and found the carbon monoxide levels were six times the recommended maximum.

All family members had fallen ill to varying degrees shortly after arriving to the home, according to the North Tahoe Fire Protection District.

In a statement, North Tahoe fire Chief Michael Schwartz said, “We are so thankful to report that this holiday disaster was averted. Situational awareness is so important. Whether you are at home or traveling, it is important (to) ensure that smoke and CO alarms are in working order anywhere you stay. It’s not a bad idea to consider bringing your own alarm when you travel, just to be safe.”

So #thankful for a happy ending to this #carbonmonoxide #co incident. Never assume you are safe, check your alarms whenever you #Travel! https://t.co/LzzUKVKQjw — North Tahoe Fire (@NTFPD_) December 3, 2019

That echoes advice that Dave Hamilton, from the Morris County Public Safety Training Academy, gave to TODAY last year.

"One of the best things you can do is take one, and put it in your suitcase,'' Hamilton said of battery-powered carbon monoxide detectors. "Travel with it. They're going to protect you."

Because, as Faris just learned, you never know if a vacation spot will have its own.