These airmen cleaned up an H-bomb disaster. Decades later, they're still fighting for benefits.

Mark 28 Thermonuclear Bomb on display at the National Museum of the U.S. Air Force.

On a winter morning in 1966, nuclear weapons fell from the sky over southeastern Spain.

High above, an American B-52 bomber on a Cold War alert mission had collided with a refueling plane mid-flight. The impact blew open the aircraft's belly, sending four hydrogen bombs sailing toward earth.

Two of the bombs partially detonated near the seaside town of Palomares, blasting craters as big as houses and coating the area in radioactive dust. Both aircraft were destroyed and seven crew members were killed.

The U.S. Air Force quietly assembled 1,600 low-ranking troops and rushed them to Palomares to clean up the mess. Among them was Anthony Maloni, then 21 years old, who arrived in the first wave.

For weeks, Maloni and his counterparts toiled in the Spanish countryside, collecting wreckage, destroying crops and shoveling soil contaminated by the explosions. Some wore thin surgical masks; others had no protection. They ate local food, drank local water and camped out in nearby tents until their work was done.

Over the following decades, signs of radiation exposure manifested in many of the airmen - everything from hair loss to blood disorders to cancers.

But when they went to the Defense Department for help, they were systematically turned away, according to a new lawsuit by Maloni and two veterans groups.

The lawsuit, filed Tuesday in U.S. District Court in Connecticut, alleges that an untold number of the airmen involved in the Palomeras cleanup have been denied disability benefits because the Defense Department has refused to turn over medical records and other data that would show the extent of their radiation exposure.

Maloni, now 72, says he developed heart disease, psoriasis, eczema, bronchitis and excruciating headaches after working in Palomares. He says he is the only one of his 10 siblings to experience such problems.

After being denied disability benefits from the Department of Veterans Affairs, Maloni sent multiple Freedom of Information Act requests to the Defense Department seeking medical records and other documents that would support his claims. The two other plaintiffs in the lawsuit, Vietnam Veterans of America and its Connecticut chapter, made similar requests on behalf of airmen who were exposed to radiation during the cleanup.

The Defense Department wrongfully withheld the records, leaving the airmen in the dark, the lawsuit alleges.

"Palomares veterans have waited decades for even basic information about the medical risks that prolonged exposure to radioactive plutonium dust carries," Patti Dumin, president of the Connecticut State Council of the Vietnam Veterans of America, said in a statement Tuesday. "They cannot wait any longer. The Pentagon owes them answers."

A Defense Department spokesman was not immediately available for comment. The department typically does not discuss pending lawsuits. The Air Force has long insisted that there was no dangerous radiation in Palomares and that crews were protected from harmful exposure during the cleanup.

The Jan. 17, 1966, accident, often called the Palomares Incident, is widely viewed as one of the worst nuclear disasters in world history.

The collision occurred as the B-52 bomber was several hours into a nuclear patrol that the U.S. military ran regularly during the Cold War. The non-nuclear portions of two of the bombs carried by the aircraft exploded on impact, blanketing a 500-acre tract of the rustic land in plutonium dust from the weapons' cores. The third bomb fell nearby and was found mostly intact. It took more than two months and a frantic search to discover the fourth, which was pulled from a 2,900-foot canyon in the Mediterranean Sea.

The whole saga has been well-documented over the years, but the complaint by Maloni and the veterans groups offers some gritty, ground-level details about the cleanup.

When the operation began, the Air Force ordered the airmen to stand shoulder-to-shoulder and walk slowly across the fields around the crash site, gleaning debris from the wreckage. They were provided no training or safety equipment, the lawsuit says.

The men were also given the unpleasant task of destroying most of the crops in the area. After pulling up garden stakes and slashing through vines with machetes, they would drop the crops into pits and dissolve them with lime or douse them in gasoline and burn them. Maloni said he recalled vomiting "from the thick, acrid smoke emanating from the burning vegetation."

The last stage of cleanup involved a massive excavation of contaminated soil. "Crews bulldozed the earth, sending clouds of plutonium-laced dust into the air," the complaint reads. Other workers spent weeks shoveling tons of soil into barrels, which were eventually transported to the United States and buried.

Radiation testing was performed hastily, according to the complaint. A medical team collected urine samples from airmen working at the crash site and conducted environmental testing, but the team had a hard time following laboratory protocols given the conditions on the ground, the lawsuit says.

The Defense Department never informed the majority of the airmen about their results and has resisted requests to do so, according to the complaint.

A 2001 Pentagon-commissioned study sought to "reconcile" some of the original tests with environmental data, in hopes of providing a more accurate account of the airmen's exposure. The report showed that some airmen did indeed have dangerously high exposure levels, but other findings were inconclusive, and the Defense Department declined to conduct a further analysis, according to the complaint.

In 2013, the Air Force created a "dose estimate methodology" for the many airmen seeking benefits for what they claimed were Palomares-related disabilities. Most were told their radiation levels were too low to have triggered maladies, according to the complaint. Some were told there was no record of them having worked at the crash site at all.

The lawsuit seeks an order compelling the Defense Department to conduct a "reasonable search" for the airmen's records and cover the costs related to the inquiry.

On the 50th anniversary of the disaster last year, the New York Times ran a pair of deeply reported articles about the lingering effects on the airmen, now senior citizens, and the village where the weapons exploded. The newspaper reviewed a trove of previously classified documents, some of which showed the radiation was so bad that nuclear monitoring equipment went "off the scales" and indicated "alarmingly high" plutonium contamination among the people involved in the cleanup.

The Times identified 40 veterans who participated in the cleanup. Twenty-one of them had cancer, and nine had died from it, according to the report.

The Air Force Medical Service responded to the the Times's stories in a statement saying that it had recently used modern methods to test the radiation risk among the veterans. "Adverse acute health effects were neither expected nor observed, and long-term risks for increased incidence of cancer to the bone, liver and lungs were low," the service said.

Victor Skaar was one of the men who was tasked with collecting urine from the troops working in Palomares. He was mentioned in the text of the veterans' lawsuit but not named as a party.

In 1983, Skaar developed leukopenia, a reduction in white blood cells. Doctors said it was brought on by his exposure to plutonium, as he told the News-Leader in Springfield, Missouri, last year. He has also fought skin cancer and prostate cancer, according to the lawsuit.

Skaar told the News-Leader that the Department of Veteran's Affairs had denied his medical claims because there was no record of him being exposed to radiation.

"Veterans my age are being ignored," he said, "because, hell, we're going to die soon anyway."