A whistleblower who sounded the alarm on safety issues with Boeing planes has died under mysterious circumstances, The Seattle Times reported on Wednesday. Joshua Dean, a former quality auditor at Boeing supplier Spirit AeroSystems, died after what the Times characterized as “a short and sudden illness.” Dean, 45, was diagnosed with pneumonia and a bacterial infection–MRSA–spending two weeks in critical condition before his death on Tuesday, his aunt told the newspaper. While working for Spirit, Dean filed a complaint with the Federal Aviation Administration alleging “serious and gross misconduct by senior quality management of the 737 production line,” according to the Times. He was fired in April 2023, alleging later to the Department of Labor that it was because he’d continued to raise concerns about manufacturing defects. “​​Our thoughts are with Josh Dean's family. This sudden loss is stunning news here and for his loved ones,” a Spirit spokesperson said. Dean’s death comes two months after that of John Barnett, a former Boeing employee who was found dead of a suspected self-inflicted gunshot wound in the middle of giving testimony in a whistleblower lawsuit against the company. Both Dean and Barnett were represented by the same South Carolina law firm, the Times reported.