The vice president and transportation secretary claimed that diversity hiring efforts had affected staffing levels among air traffic controllers, but there is no evidence that such efforts played a role in the crash.

There is no evidence that diversity efforts played a role in the crash, and his statements disregarded his own administration’s hiring policies.

In a briefing that recalled his most extreme first term remarks, President Trump said without any evidence that diversity initiatives caused the midair collision.

President Trump’s remarks, suggesting without evidence that diversity in hiring and other Biden administration policies somehow caused the disaster, reflected his instinct to immediately frame major events through his political or ideological lens.

President Trump’s directive is supposed to exempt national security and public safety positions, but the F.B.I. has put an immediate hiring freeze in place.

Government agencies that shrank in President-elect Trump’s first term have mostly bounced back, and some have become even larger.

Airlines have been increasingly outsourcing repair and upkeep work to other countries, but experts and consumer groups disagree about its impact on safety.

The industry is pumping ever more oil and natural gas, but it is doing so with only about three-quarters as many workers as it employed a decade ago.

Hiring a private fire crew costs thousands of dollars a day, and most work through government contracts or with insurance companies. Some wealthy property owners are calling them in directly.

A December gain of 256,000 blew past forecasts, and unemployment fell to 4.2 percent. But markets recoiled as interest rate cuts seemed more distant.