2 whistleblowers warned Boeing airplanes aren't safe. Both are now dead.

The aerospace company Boeing is in the hot seat at the moment following a series of concerning plane incidents and the deaths of two whistleblowers. 

Two men were testifying against Boeing — alleging management ignored their complaints of serious manufacturing quality defects and safety issues. Now both are dead.

Joshua 'Josh' Dean was a former quality auditor at Boeing supplier Spirit AeroSystems. 

He said he had noticed safety issues and manufacturing defects during an audit of his on Boeing's 737 MAX, adding that he had flagged his concerns with Spirit in late 2022.

Dean was fired by Spirit in 2023. He subsequently filed a complaint with the US' Department of Labor and the Federal Aviation Administration, alleging that his termination was in retaliation for raising safety concerns. In his complaint he said there was "serious and gross misconduct by senior quality management of the 737 production line" at Spirit. Dean became the first Boeing whistleblower. 

Watch: The Boeing whistleblowers' testimonies. Post continues below.

By all reports, Dean had been in decent health up until two weeks ago. He was 45 years old and his family said he was in good spirits and lived a healthy lifestyle.

He came down with a "sudden, fast-spreading infection," soon presenting to hospital and being listed as in a critical condition for the next two weeks. Speaking to the Seattle Times, his aunt said Dean's illness began when he had trouble breathing, quickly being intubated and developing pneumonia, followed by a serious bacterial infection, MRSA.

He died from complications of the infection. 

"It was brutal what he went through," his aunt said. "Heartbreaking."

His sister wrote on Facebook: "My handsome brother Joshua passed away this morning and is with our baby brother. I don't know how much more my family can take. I don't know how much more I can take honestly."

A Spirit spokesperson [Spirit being a Boeing supplier] told the Seattle Times: "Our thoughts are with Josh Dean's family. This sudden loss is stunning news here and for his loved ones."

In a statement to PEOPLE, Dean's lawyers said: "Our thoughts and prayers are with Josh and his family. He possessed tremendous courage to stand up for what he felt was true and right and raised quality and safety issues."

Dean was represented by the same law firm that represented another Boeing whistleblower, John 'Mitch' Barnett.

Joshua Dean and John 'Mitch' Barnett. Image: Facebook/Netflix.

62-year-old Barnett had worked for Boeing as a quality manager for most of his 32-year career, performing routine checks on machines and identifying solutions to issues. Part of this job meant he was focused on any potential safety issues — which he said he found, and flagged with Boeing directly.

Feeling as though his worries were falling on allegedly deliberate deaf ears, Barnett joined the whistleblower suit against Boeing. He also featured in the 2022 Netflix documentary Downfall: The Case Against Boeing.

On March 9, Barnett, was found dead in the US city of Charleston, where he was delivering a deposition in connection with his whistleblower lawsuit.

He was found deceased in a truck parked in a hotel parking lot with a gunshot wound to the head. Officials ruled his death to be a suicide.

Barnett's lawyers have challenged that ruling. They released a statement saying: "We didn't see any indication that he would take his own life. No one can believe it. The Charleston police need to investigate this fully and accurately and tell the public. No detail can be left unturned."

A friend of Barnett's claimed to ABC that Barnett had previously warned her: "If anything happens to me, it's not suicide."

Following Barnett's death, Boeing representatives said: "We are saddened by Mr Barnett's passing, and our thoughts are with his family and friends."

The heat has been on Boeing in recent years.

In 2018 and 2019, two 737 MAX planes were involved in fatal crashes, which killed 346 people.

US regulators are also now investigating Boeing after a mid-air door-panel blowout in January on a Boeing 737 MAX 9. The incident occurred on an Alaska Airlines flight, passengers saying there was a "huge bang" before a massive hole opened up in the side of the plane, minutes into the flight. Wind and noise filled the cabin, clothes and phones were ripped from passengers and hurled into the void. It's a miracle no one died. 

That same month an ANA Boeing 737-800 plane had to turn around and land in Japan after a crack was found on the cockpit window midair.

In March, 50 people were hurt onboard a Boeing 787-9 plane due to what was initially described as "strong movement" as the plane was flying from Australia to New Zealand.

Investigations continue.

Feature Image: Getty.