Police evacuated a building in West Babylon after two people were overcome by high levels of carbon monoxide today.

Fire officials say an office building on Route 109 was filling up with dangerous levels of carbon monoxide and no one inside knew about it until a 911 call was made about an unrelated accident in the building.

News 12 was told that someone called 911 after a woman fell and injured her shoulder in one of the offices. When firefighters responded, their CO detectors alerted them that there was a lethal level of CO in the building.

West Babylon Fire Chief Peter McArdle told News 12 that they had reading of 200 parts per million in the back of the building's warehouse. McArdle called the reading "very high."

Firefighters immediately evacuated 27 people from the building. A total of seven people were taken to the hospital as a precaution.

Responders also ventilated the building to rid it of the odorless gas.