(CHICAGO) Chicago’s Board of Education is facing at least its ninth lawsuit since a carbon monoxide leak at Northwest Side school last fall that sent dozens of children to hospitals.

Maria Bogojel filed the suit Monday in Cook County Circuit Court on behalf of her daughter, a student at Prussing Elementary School, 4650 N. Menard Ave.

About 9:30 a.m. Oct. 30, 2015, emergency crews were called for a report of a sick child in the gymnasium, fire officials said at the time. The school was evacuated when high carbon monoxide levels were detected in the hallways.

At least 71 children and seven adults were taken to various hospitals with dizziness, nausea and abdominal pain. None of the illnesses were thought to be life-threatening.

The school’s boiler was the source of the leak, Chicago Public Schools officials said at the time. Representatives did not immediately return requests for comment on the latest lawsuit Monday evening.

Bogojel claims her daughter suffered serious injuries and that school officials should have better maintained the building’s boiler vent system. The three-count negligence suit seeks more than $150,000 in damages.

Six other Prussing families filed suit against the school board in November 2015, followed by two more this past August.