Boeing is being sued by three flight attendants who claimed they got sick by the toxic air that leaked into the cabin. The attendants blamed a design flaw in the company built airplane for the toxic air leak.

According to the lawsuit filed by the three attendants against Chicago based Boeing Co. in Cook County Circuit Court Tuesday, the plane utilizes a “bleed air system,” which captures air from outside of the engines. This air that enters the cabin may be contaminated with various chemicals, The Chicago Tribune reported citing the lawsuit.

The lawsuit obtained by the Tribune cites an incident from February 2018, where passengers on a Boeing 767-300 Delta flight from Frankfurt, Germany to Detroit became sick due to the contaminated, prompting the captain to change the course of the flight.

The incident caused the flight attendants to suffer loss of wages and wage-earning capacity in the past and in the future. The lawsuit also alleges that though Boeing officials were aware of the flaw, the flight attendants were not notified about the health concerns that came with the contaminated air.

“For more than sixty years, Boeing has been put on notice, on more than a hundred occasions, that its bleed air system airplanes are unreasonably dangerous and can cause serious acute and permanent injuries to flight crew and passengers,” the lawsuit, which was obtained by the Tribune, alleges.

The flight attendants are seeking damages over $50,000 and a jury trial. According to the lawsuit, flight attendants still suffer from various health problems caused due to exposure to toxic air which include headaches, nausea, and confusion.

A similar lawsuit was filed in 2015 by the same law firm, and it was settled last month, the Chicago Tribune reported.

Following months of delay, Boeing plans the first flight for its new long-range 777X on Thursday
Following months of delay, Boeing plans the first flight for its new long-range 777X on Thursday AFP / MANDEL NGAN