Virginia Beach, VA — Nikki James Zellner started to panic last Thursday when she pulled onto the street of her children’s day care and saw a host of fire trucks and ambulances.

She’d gotten word from Kids Town Learning Center to come pick up her two sons, ages 3 and 4, after a carbon monoxide leak was detected.

The kids and staff had all been evacuated to the building next door — snow was falling that day, so it was too cold to stand outside — and some were being checked by medics. She noticed her younger son Owen’s skin was a little purplish red, and a firefighter told her to take him over to an ambulance.

“His face didn’t look like that when I dropped him off that morning, that’s all I know,” Zellner said. “When we walk over to the ambulance, I saw a teacher with oxygen strapped to her face.”

It wasn’t until a bit later, waiting for Owen to be cleared — he was, quickly — that Zellner heard that some teachers at the day care had started getting headaches and feeling nauseated in the late morning, and that a young girl had “kept going limp,” though it’s unclear why.

One of the teacher’s husbands brought a carbon monoxide detector a few hours later to test, and when it was plugged in, the alarm went off immediately. The building was evacuated, and no one was seriously injured.

Zellner would later learn what shocked her the most: Carbon monoxide alarms were not required to be in the day care, or in most schools and child centers in the commonwealth.

“You have to double wrap your breast milk for your babies to go there,” Zellner said. “I’d be under the impression they’d have working carbon monoxide detectors.”

Despite code added in recent years making the detectors mandatory in new buildings, including for educational purposes, it doesn’t apply to those built before 2015.

At least not yet. Zellner’s been working tirelessly to make that happen, creating a petition on that’s racked up nearly 1,000 signatures in a few days. She’s also contacted lawmakers, some of who said they were shocked the detectors aren’t required in day cares and schools and already plan to introduce legislation to change it.

“A whole lot of people are in the dark that their children aren’t protected from this,” Zellner said. “They’re just assuming they are.”

Carbon monoxide is an odorless, colorless, deadly gas.

The most common symptoms of carbon monoxide poisoning, according to the Centers for Disease Control and Prevention, are headaches, dizziness, weakness, vomiting, an upset stomach, chest pain and confusion. They’re often described as “flu-like.” The young, the old and those with existing respiratory conditions are particularly vulnerable.

People who are sleeping — such as small children in a nap room — can die before experiencing symptoms.

Kids Town director Patti Pirrone declined to comment for this story, but in an email to parents on Monday, she said the source of the recent leak was a fault in the heating system that has since been fixed. Her email, which did not reveal the level of the gas that was released, noted that despite the lack of a requirement, the day care had immediately placed a detector in every classroom as well as in the kitchen and offices.

A week later, Friday morning, the new detectors went off. Another leak was found and the day care closed for the day.

The Virginia Beach Fire Marshal’s office said in a statement “that every structure that has a combustible device that produces carbon monoxide should have a detector to warn of a possible problem.”