A former Boeing Co. employee, who raised concerns about the company’s production standards at its North Charleston 787 Dreamliner factory, has been found dead, according to the BBC.

John Barnett, who worked at Boeing for 32 years until his retirement in 2017, died on March 9 from a self-inflicted wound, as reported by the BBC. His death was confirmed by the Charleston County Coroner.

Boeing expressed sadness upon hearing of Barnett’s death, stating that their thoughts are with his family and friends.

Prior to his death, Barnett had been providing evidence in a whistleblower lawsuit against Boeing. He was scheduled for further questioning on Saturday but did not appear. Hotel staff found him dead in his truck in the hotel car park.

In 2019, Barnett was mentioned in a New York Times article highlighting problems at the North Charleston factory, including faulty parts and metal shavings left inside jets. Barnett reported finding metal slivers hanging over the wiring that controls flight controls.

Boeing’s safety record has come under scrutiny following a Jan. 5 incident involving a 737 Max 9 operated by Alaskan Airlines. The plane experienced a door plug blowout shortly after takeoff, but no one was injured. Boeing has acknowledged it can’t locate records of the work done on the failed panel and suggested that company procedures weren’t followed. US regulators have given Boeing 90 days to address what they’ve called “systemic” quality-control issues, and the Justice Department has launched a criminal investigation into the incident.