Fire and utility crews were on scene this morning dealing with a carbon monoxide leak at Clifton High School on Colfax Avenue.

The leak was noticed around 7 a.m., well before students entered the school. Class was canceled for the entire high school today. About 3,000 students go to the school.

The deputy fire chief says there was work being done on the boiler system at the school. Generally, the carbon monoxide gas is vented through a flue outside of the school. Those fumes were unintentionally leaked invented back into the school. Plus, a separate gas leak in a pipe nearby was also a cause for concern. 

A variety of windows were open around the school to diffuse the gases and bring them outside the school. News 12 was told that the levels of carbon monoxide were at 500, which is very high.