A former Boeing employee turned whistleblower has died after a sudden illness, his family announced on Tuesday.

Joshua Dean, a former Spirit AeroSystems employee, had accused the aircraft manufacturer of ignoring defects in the production of the 737 MAX, a series whose reputation has been marred by a series of crashes and safety issues in recent years.

Dean is the second Boeing whistleblower to die suddenly, after Josh Barnett was found dead less than two months ago. According to South Carolina authorities, Barnett died of an apparent self-inflicted gunshot wound.

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