House Oversight Committee Chairman Rep. James Comer, R-Ky., detailed a possible national security crisis involving 11 high-level scientists who have vanished or died since 2022.

House Oversight Committee Chairman James Comer, R-Ky., warned Sunday that "something sinister could be happening" after 11 scientists mainly tied to the U.S. nuclear and space research programs reportedly died or went missing under mysterious circumstances, raising urgent national security concerns.

Comer said on "Fox & Friends Weekend" that when he first heard about the disappearances, they sounded like "some kind of crazy conspiracy theory." But the details of the case changed his mind and prompted him to alert multiple government agencies.

Rep. James Comer, R-Ky., chairman of the House Oversight and Accountability Committee, told "Fox & Friends Weekend" that he sent letters to the leaders of several government agencies seeking information related to the "mysterious" deaths and disappearances of scientists in recent years. (Graeme Sloan/Bloomberg via Getty Images)

"We've put a notice out to the Department of War, to the FBI, to NASA, to the Department of Energy, that we want to know everything that they know about what happened with these scientists, because those four agencies were predominantly the agencies that those 11 individuals were affiliated with. And we want to try to piece this together."

Comer plans to bring the leaders of these offices before Congress, but said he sent the letters first to allow them time to ensure their testimony would not compromise any potentially classified investigations.

He said he hoped anyone with information would bring it to the Oversight Committee, and that anyone affiliated with America's nuclear program should be on alert, given the possible security risks to the nation.

STRING OF SCIENTIST DEATHS, VANISHINGS FUELS EXPERT TALKS OF SHADOW OPS AND SILENCED SECRETS: 'VERY SERIOUS'

Jason Thomas, left, Melissa Casias, center, and Frank Maiwald are among scientists whose deaths or disappearances have drawn scrutiny as officials review whether any cases are connected. (Fox News: Sierra Casias: Legacy.com)

"We know there are many countries around the world that would love to have our knowledge and nuclear capabilities. And these are the people that were at the forefront of it, and they're either dead or missing."

Missing or deceased figures include experimental propulsion researcher Amy Eskridge, 34; retired Air Force Maj. Gen. William "Neil" McCasland, 68; NASA scientist Monica Jacinto Reza, 60; contractor Steven Garcia, 48; astrophysicist Carl Grillmair, 47; Massachusetts Institute of Technology physicist Nuno Loureiro, 47; NASA engineer Frank Maiwald, 61; Los Alamos–linked employees Melissa Casias, 53, and Anthony Chavez, 79; NASA researcher Michael David Hicks, 59; and pharmaceutical scientist Jason Thomas, 45.

11TH SCIENTIST DEATH EMERGES IN STRING OF MISSING, DEAD OFFICIALS WITH ACCESS TO US SECRETS

In response to the renewed public attention, President Donald Trump has vowed to investigate the mysterious disappearances and deaths of these scientists.

"I hope it's random, but we're going to know in the next week and a half," Trump told reporters Thursday. "I just left a meeting on that subject."

Additionally, the National Nuclear Security Administration (NNSA) previously told Fox News Digital it is looking into the cases.

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"NNSA is aware of reports related to employees of our labs, plants, and sites and is looking into the matter."

Fox News Digital's Julia Bonavita and Morgan Phillips contributed to this report.

Max Bacall is an Associate Editor for the Flash/Media/Culture team at Fox News Digital.

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