(Photo : (Photo by Julie Denesha/Getty Images))
Spirit AeroSystems said the company’s thoughts were with his family.

Whistleblower Joshua Dean, who had accused a Boeing supplier of overlooking defects in the production of the 737 MAX, has died from a "sudden illness," making him the second whistleblower to die in as many months. 

Dean's mother posted on her Facebook account last month that her 45-year-old son was "fighting for his life" after contracting pneumonia and suffering a stroke following an MRSA infection. Dean passed away on Tuesday morning, according to Aljazeera. 

The former Spirit AeroSystems employee who claimed he was fired in an act of revenge for flagging lax standards at the company's Wichita, Kansas, manufacturing plant had filed a complaint against Spirit with the Federal Aviation Administration alleging significant failures at its production facility and had also recently testified in a shareholder lawsuit against the company.

Aerosystems has been under investigation since the door panel that flew off a 737 MAX 9 aircraft mid-flight in January was found to have been produced in their facility.

The near-catastrophe, including Alaska Airlines Flight 1282, which has been the subject of multiple inquiries, was the latest in a string of incidents causing alarm over safety standards at Boeing.

Dean had previously told NPR that he believed his firing was used as an example to others who were contemplating speaking out, according to Aljazeera.

"If you are too loud, we will silence you," he said in February.

Dean's passing comes less than two months after Boeing whistleblower John Barnett was found dead from an apparent self-inflicted gunshot wound.

Barnett, 62, who was also fired for exposing issues with the 787 Dreamliner, was in the midst of a deposition in a lawsuit against Boeing at the time of his death.