The sky is falling — at least on Boeing.

A second whistleblower has died under mysterious circumstances, just two months after another one allegedly shot himself in the head — and the attorneys for both men hope their deaths don’t scare away the at least 10 other whistleblowers who want the company to clean up its act.

Joshua Dean, 45, a former quality auditor at Spirit AeroSystems which assembles fuselage sections for Boeing, died Tuesday morning from a fast-growing mystery infection.

Dean’s death comes less than two months after Boeing whistleblower John Barnett, 62, died from an apparent self-inflicted gunshot wound on March 9.

Barnett, who had worked for Boeing for 32 years, was found dead in his Dodge Ram truck holding a silver pistol in his hand in the parking lot of his South Carolina hotel after he failed to show up for the second part of his testimony for a bombshell lawsuit against the company.

At the same time, Boeing said last month that it lost $355 million on falling revenue in the first quarter, another sign of the crisis gripping the aircraft manufacturer as it faces increasing scrutiny over the safety of its planes and accusations of shoddy work from a growing number of surviving whistleblowers.

It was announced abruptly in March that Boeing CEO Dave Calhoun would step down by the end of the year in a move widely seen as a reaction to the ongoing safety crises.

Brian Knowles, a Charleston, South Carolina, attorney who represented both Barnett and Dean hope their deaths were not in vain.

“These men were heroes. So are all the whistleblowers. They loved the company and wanted to help the company do better,” Knowles told The Post.

“They didn’t speak out to be aggravating or for fame. They’re raising concerns because people’s lives are at stake.”

Knowles and others inside the Boeing scandals are hesitant to speculate about conspiracy theories swirling around the two whistleblower deaths.

“I knew John Barnett for seven years and never saw anything that would indicate he would take his own life,” Knowles told The Post.

“Then again, I’ve never dealt with someone who did (commit suicide.) So maybe you don’t see the signs. I don’t know.”

“I knew John Barnett for seven years and never saw anything that would indicate he would take his own life,” Knowles told The Post.

Knowles pointed out that the Charleston, SC police are still wrapping up their investigation of Barnett’s death — and that it may take some weeks for tests to reveal more about Dean’s passing.

“It’s a stunning loss,” Spirit AeroSystems spokesman Joe Buccino said of Dean. (The company is not to be confused with Spirit Airlines.) “Our focus here has been on his loved ones.”

Buccino insisted that Spirit “encourages” employees to come forth with their concerns and that they are then “cloaked under protection.”

A Boeing spokeswoman declined to answer questions on Barnett but in a statement, said that OSHA had determined Barnett was not retaliated against, and that the company’s own analysis found that the issues he raised “did not affect airplane safety.”

“We are saddened by Mr. Barnett’s passing and our thoughts continue to be with his family and friends,” the statement said.

“We encourage all employees to speak up when issues arise. Retaliation is strictly prohibited at Boeing.”

It’s news to other Boeing whistleblowers that Boeing and Spirit “encourage” workers to speak out.