Williston, VT – A carbon monoxide leak forced Williston residents out of their apartments Monday.

First responders are investigating what caused what they’re calling significantly high levels of the gas.

Williston Fire says a resident of the building on Seymour Street called them Monday night. They say he thought his carbon monoxide detector was broken when it wouldn’t stop beeping, but that when he installed a new one and it went off too, he knew there was a problem.

First responders pulled the fire alarm and evacuated the building when they found high levels of carbon monoxide at around 6 p.m.

Investigators are still trying to figure out what caused the carbon monoxide leak, but they suspect it may be heating furnaces.

Williston Fire officials say they don’t know exactly how many people live in the building but there are 12 apartment units. They tell us they don’t believe anyone got sick from the high levels of the gas.

It took a couple of hours to air out the building, but residents still aren’t allowed back inside since the heat is off.