A Puerto Rico Air National Guard military cargo plane crashed near Savannah, Georgia shortly after takeoff Wednesday, killing all nine people on board. It is the latest in a series of fatal airborne military incidents in the United States over recent years, further underscoring the callous disregard for human life in the upper echelons of the world’s most lavishly-funded military.

The Puerto Rico Air National Guard WC-130 was flying from Savannah, Georgia to Tucson, Arizona when the four-turboprop plane suddenly stalled in midair and banked sharply to the left before nosediving directly into Georgia state Highway 21. Five bodies have thus far been recovered from the wreckage and all nine people on board—five crew and four other military personnel—are presumed dead. Fortunately, no one driving on the stretch of highway at the time was injured.

A spokesperson for the Georgia Air National Guard told reporters that the plane was manufactured in the 1970s, though it was later reported that the plane was at least sixty years old.

Major Paul Dahlen, a spokesperson for the Puerto Rico National Guard (PRNG), said the plane had undergone what he called “routine maintenance” at a hangar in Savannah for “a number of days” before the incident but refused to specify what type of maintenance the plane had received. Subsequent reporting indicates that the aircraft had been at the facility for at least a month.

Dahlen said that the cause of the crash is unknown and that the incident is being investigated by the National Guard Bureau and the US Air Force.

The WC-130 was destined for the Aerospace Maintenance and Regeneration Group (AMRG) at Davis-Monthan Air Force Base in Arizona. While the PRNG initially described the flight as a “training exercise,” it was later revealed that the C-130 was being flown to the airbase to be retired. Known as “The Boneyard,” the AMRG stockpiles old military aircraft and spacecraft nearing the end of their lifespan.

The crash has been met with widespread anger in Puerto Rico, which remains in a state of utter devastation following the catastrophic damage inflicted by Hurricane Maria last year and official indifference on the part of the US government.

Even before the hurricane, Puerto Rican workers faced a severe economic crisis, with high unemployment and low wages coupled with one of the highest costs of living in the United States. These economic conditions have been exacerbated by a public debt crisis and the Jones Act of 1898, which mandates that only US-flagged vessels may dock at overseas ports of the United States.

Puerto Rico Governor Roberto Rosselló announced nine days of mourning in response to the crash, during which flags will fly at half-mast outside government buildings across the US colony.

Carlos Navaez, a close friend of the pilot, told Noticias NY1 that his friend had expressed concern over the safety of the aircraft he was working with, saying that the planes he flew are the oldest in the United States. The pilot told him that some of the planes have been rebuilt several times over the decades.

Wednesday’s crash represents just the latest in a series of fatal accidents involving military aircraft in the United States over recent years. In July, another C-130 crashed in rural Mississippi on a flight from North Carolina to California, killing 15 Marines and one Navy Corpsman. An investigation into that crash is still ongoing.

In June 2016, a Blue Angels exhibition jet crashed during a Tennessee air show, killing the pilot. Luckily, nobody on the ground was injured. A U-2 spy plane crashed in California in September of the same year, killing one pilot and wounding the other. In April 2017, a single-engine jet crashed and killed three Air Force members.

In March of this year, two pilots died following the crash of their US Navy F/A-18 Super Hornet off the coast of Florida. A US Air Force Flight Demonstration F-16 crashed in Nevada last month, killing the pilot.

According to the Military Times, such incidents have increased by 40 percent since 2013 despite the hundreds of billions of dollars spent on the US military budget every year.