TOM LEONARD: These scientists worked for top secret nuclear and space programmes. Now they are all missing or dead

By TOM LEONARD, US CORRESPONDENT Published: 01:02, 24 April 2026 | Updated: 01:03, 24 April 2026 Even before the charred body of NASA engineer Joshua LeBlanc was found in his burnt-out Tesla, his family had raised the alarm about his mysterious disappearance. The 29-year-old electrical engineer working on nuclear propulsion projects at the space agency’s research laboratory in Huntsville, Alabama, had uncharacteristically failed to turn up for work and family feared LeBlanc, who had left his phone and wallet at home, had been abducted. Tesla tracking technology revealed his car had been parked at the local airport last July for four hours on the morning of his death, before being driven towards his office. It crashed on a rural road and the car burst into flames. LeBlanc is far from the only scientist in a sensitive field of work linked with Nasa to have gone missing or died in odd circumstances. In fact, it is claimed that 11 people involved in America’s space and nuclear programmes have disappeared or died in unusual or unexplained circumstances in recent years. The oddest thread in this puzzling tale is that a number of them vanished after simply heading out for a walk. Monica Reza was hiking with two friends in California’s Angeles National Forest last June when she disappeared into thin air. It had been a perfectly normal day and, according to one of her companions, he’d last seen her just 30ft behind him, smiling and waving. When he next turned around, she was gone. Rescue teams spent days searching for Reza but could find no trace of the 60-year-old aerospace engineer. She was involved in even more hush-hush work than LeBlanc. As director of the Materials Processing Group at Nasa’s Jet Propulsion Laboratory, she had developed a ‘super-alloy’ metal used in rockets – so her sudden disappearance might also have been viewed as intrinsically suspicious. Astrophysicist Carl Grillmair was shot dead outside his house in a town in rural California Nasa scientist Frank Maiwald's death remains unexplained. He had won multiple awards Lt Jaime Gustitus, 25, worked as an air force research officer before dying in a murder-suicide Retired Los Alamos nuclear scientist Anthony Chavez, 78, disappeared one day without a trace So, is this a series of sad coincidences – or is there something else going on? Politicians in Washington and former law enforcement chiefs are among those who believe it could be the latter. Last Wednesday, the Trump administration indicated that the deaths had finally registered on its radar, with White House Press Secretary Karoline Leavitt telling reporters that she would speak to the relevant federal agencies. The FBI is reportedly now leading a multi-agency investigation into the deaths and disappearances. All the individuals involved are linked by a web of workplaces and fields of research. In some cases, they had been direct colleagues. Reza’s groundbreaking research work, for instance, was financed and overseen by the Air Force Research Laboratory which, at the time, was commanded by former US Air Force Major-General William Neil McCasland. Now, he has gone missing, too – vanishing without trace after leaving his home in Albuquerque, New Mexico. His disappearance has sparked particularly intense interest online because, after his 2013 retirement from the military, Maj-Gen McCasland was involved in the investigation of UFOs. The 68-year-old was last seen by his wife, Susan, on February 27 just after 11am. She returned from a short medical appointment to find him gone, according to police. Like Reza a keen hiker, he appeared to have gone out to run around local trails in hiking boots, taking with him a backpack, his wallet and a .38 calibre revolver and holster. Curiously, he left behind his mobile phone, prescription glasses and Smart watch. A grey US Air Force sweatshirt was discovered just over a mile from McCasland’s home ten days later, although his family was unable to confirm whether it was his. His disappearance also prompted a major manhunt which has yet, after weeks of searching that included a door-to-door check of 700 surrounding homes, to turn up any trace of him. Steven Garcia, 47, was a security guard at a sensitive installation before he went missing Nasa researcher and nuclear engineer Joshua LeBlanc, 29, was killed in a Tesla crash UFO expert Major-General William Neil McCasland, 68, suddenly disappeared without a trace Senior jet and asteroid research scientist Michael Hicks, 59, died in mysterious circumstances The general’s last military posting was to command the Air Force Research Laboratory, which is based at Wright-Patterson Air Force Base near Dayton, Ohio. In this role, he oversaw highly classified space weapons programmes. Marik Von Rennenkampf, a former national security analyst in the Obama administration, described the base as ‘where all the super-secret research happens’. The base is rumoured – despite Air Force denials – to be where alien remains and debris from extraterrestrial craft, allegedly recovered from the famous 1947 crash site near Roswell, New Mexico, are stored. McCasland had also commanded a research department at Kirtland Air Force Base in New Mexico – a sparsely populated desert state long connected with UFO claims – and led a department of NASA’s Space Vehicle Directorate, as well as working at the Pentagon. Plenty there for the more conspiracy-minded to get their teeth into. The UFO world was further excited by the fact that McCasland disappeared only six days after Trump promised to release eagerly awaited government files on extraterrestrial life and spacecraft. Ross Coulthart, a journalist who has investigated UFO claims, described the timing as ‘screechingly relevant’ and called McCasland ‘a man with some of the most sensitive US military intelligence secrets in his head’. Meanwhile, McCasland’s wife went on Facebook to counter ‘misinformation’ about him. She said he didn’t have dementia and, though she acknowledged he once had ‘access to some highly classified programmes and information’, she found it ‘quite unlikely’ that he was ‘taken to extract very dated secrets from him’. Her husband had no ‘special knowledge’ about any alien or UFO remains at the Wright-Patterson base, she insisted. County sheriff John Allen said tip-offs he had received included ‘some outlandish theories’. Those theories are gathering steam. Rocket specialist and Nasa engineer Monica Reza, 60, is also missing with no leads to follow Plasma physicist and nuclear scientist Nuno Lureiro, 47, was killed in a shooting  Melissa Caslas, 53, was an administrative assistant at Los Alamos before she disappeared Four days after the disappearance of Monica Reza, Melissa Casias, 53 – an administrative assistant at Los Alamos National Laboratory, the top secret nuclear research facility in New Mexico which developed the atomic bomb in the 1940s – also went missing. Although there’s no direct connection between Casias and McCasland or Reza, her lab reportedly works closely on national security projects with the nearby Kirtland Air Force Base, whose research facility Gen. McCasland once commanded. Casias, a keen bow hunter, had reportedly told her husband she would work from home on the day she went missing in Ranchos de Taos. She was later seen walking along a highway three miles away.Her family, who said she had financial and personal problems, later discovered she’d left her work and private phones at home – along with her car, keys and purse – with their contents erased. ‘Her job links her to missing retired Air Force Gen. William McCasland, amid a pattern of disappearances and deaths of high-clearance individuals since June 2025,’ says Manifested Search Team, a charity that tries to track down missing people. Chris Swecker, a former FBI Assistant Director, told the Daily Mail he is concerned that Casias’ vanishing may be part of a pattern along with those of Reza and Gen. McCasland, although he also acknowledges it could yet turn out to be coincidence. ‘You can say these are all suspicious and these are scientists who have worked in critical technology,’ he said. Calling on the FBI to take over the investigation, he said it was plausible for hostile powers to use kidnapping or assassination to extract information from Americans involved in such militarily valuable research. The mystery doesn’t stop with this trio. Only weeks before the Casias disappearance, in May 2025, Anthony Chavez, 78, who had also worked at the Los Alamos laboratory until his retirement, vanished in similar circumstances. He also reportedly left his home in Los Alamos for a walk one morning, leaving behind his wallet and phone. His family told police his disappearance was ‘out of character’ but didn’t initially consider him to be in danger. Like Casias, he hasn’t been seen since. The same applies to Steven Garcia, who – like Gen McCasland – disappeared from his home in Albuquerque, New Mexico, on foot and only carrying a handgun, on August 28 last year. Garcia, 47, was a security guard at a New Mexico facility of the Kansas City National Security Campus, another highly sensitive federal government installation, this one devoted to manufacturing most of the non-nuclear components of America’s nuclear weapon arsenal. Officials have said Garcia may have posed a danger to himself but have not provided further details, or the nature of his work. There are other deaths that some believe must also be considered. Nuno Loureiro, an acclaimed Portuguese nuclear scientist and plasma physicist was shot dead at his home in a Boston suburb in December last year. Loureiro, 47, did his PhD at Imperial College London and had previously worked at the UK Atomic Energy Authority’s Culham Centre for Fusion Energy. Authorities say the gunman was a former classmate at Brown University who later killed himself. Although some speculate that it might have been professional jealousy, the killer’s motive has yet to be confirmed. On February 16, astrophysicist Carl Grillmair, 67, was shot dead on the front porch of his isolated home in Llano, a rural community in Los Angeles County, California. He worked at the California Institute of Technology but, like Reza, had also done important research financed by NASA’s Jet Propulsion Laboratory. A local man has been charged with the killing but, again, a motive has yet to be disclosed. Last October, Lieutenant Jaime Gustitus, 25, who worked at the Air Force Research Laboratory once led by Gen McCasland in Ohio, was killed in an apparent double-murder suicide. Her killer, Jacob Prichard – who worked on the same base – also murdered his wife Jaymee before killing himself. Online sleuths have delved further back in time claiming to find more evidence of a trend. In July 2023, Michael Hicks, a senior research scientist at the Jet Propulsion Laboratory died aged 59 but the cause of death was never made public and no record exists of an autopsy. Hicks had worked on the DART Project, NASA’s research into whether dangerous asteroids could be deflected away from Earth. He had also been involved in Deep Space 1, a NASA mission in the late 1990s to test various ‘high-risk’ technologies in space. The following year, a prominent colleague of Hicks named Frank Maiwald also passed away in undisclosed circumstances – again relatively young at 61 and again with very little public acknowledgement. The scientist was described in an obituary as a multi-award-winning expert who had chiefly worked on developing a spectrometer capable of peering deep into outer space. Clearly, some of these sudden or unexplained deaths and disappearances are rather more mysterious than others. The documented murders, for instance, appear to involve suspects who have no connection with the sort of dark forces that might have targeted the victims because of their sensitive scientific work. The absence of details about some of the other deaths could simply be down to a desire for privacy. Given NASA and its contractors, such as the Jet Propulsion Laboratory, together employ nearly 60,000 people, sometimes odd things will happen to a few of them, say sceptics. But the disappearances are surely unusual, particularly when they’ve occurred so close together and share so many similarities. They are also happening at a significant moment: with NASA accelerating its Artemis missions and China rapidly advancing its lunar ambitions, competition for technological supremacy beyond Earth has become more geopolitically charged than at any time since the Cold War. And it’s undeniable that foreign powers – particularly China but also North Korea and Iran – have a history of targeting the US technology sector and its scientists, especially those in rocket development. ‘The disappearance of multiple scientists and military personnel with ties to advanced research is deeply concerning,’ said Representative Eric Burlison. He said the areas of research involved are ‘all critical for our national security’. He went on: ‘The string of people that have left their homes without their car keys, without their phones and left everything behind, that in and of itself is strange.’ Congressman Tim Burchett told the Daily Mail he saw a pattern in these seemingly unrelated deaths and disappearances, saying that the work several of them were doing has been linked to theories about extraterrestrial spacecraft. ‘I think we ought to be paying attention to it,’ he said. Little green men or not, time may tell whether this is just a bizarre coincidence – or something far more sinister. No comments have so far been submitted. Why not be the first to send us your thoughts, or debate this issue live on our message boards. By posting your comment you agree to our house rules. Do you want to automatically post your MailOnline comments to your Facebook Timeline? Your comment will be posted to MailOnline as usual. Do you want to automatically post your MailOnline comments to your Facebook Timeline? Your comment will be posted to MailOnline as usual We will automatically post your comment and a link to the news story to your Facebook timeline at the same time it is posted on MailOnline. To do this we will link your MailOnline account with your Facebook account. We’ll ask you to confirm this for your first post to Facebook. You can choose on each post whether you would like it to be posted to Facebook. 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