(NewsNation) — The mother of a Navy SEAL candidate who lost his life during training is taking on the U.S. military to get some answers. And she’s a mom on a mission.

Kyle Mullen, 24, died Feb. 4 during the notoriously brutal training period known as “Hell Week” in California.

Three months later, there are still no autopsy results.

Regina Mullen wants to know what happened. And she wants to make sure that it won’t happen to anyone else’s son, worried that unless the Navy makes some major changes, more SEAL trainees are going to die.

Regina says her son was her best friend and against her wishes, he wanted to be a Navy SEAL.

“I didn’t want him to go. I begged him not to go,” she said. “I just … didn’t want anything to happen to my son.”

Regina Mullen said she had a mother’s intuition.

“Actually, I did,” she said. “I said, ‘The Navy’s gonna kill ya’ and he said, ‘No, ma, you’re being ridiculous.’”

As smart as he was athletic, her son lettered six times in football and basketball at his New Jersey high school.

He seemed the perfect candidate to join an elite fighting force until something went wrong.

In February, near the end of the infamous “Hell Week” near San Diego, Mullen says her son was in respiratory distress and help was not being called.

She’s a registered nurse and convinced that she knows exactly what he died from — a form of pneumonia called sipe, which is caused by water buildup in the respiratory system.

“Swimming-induced pulmonary edema,” she said. “He was found spitting up blood. In pain from breathing. He could barely breathe.”

“They’re very discouraged to call 911,” she continued. “He asked to lay down. And he died in a 19-year-old boy’s arms. He turned blue.“

Mullen says her son confided in her at one point that fellow trainees were relying on performance-enhancing drugs to get through. She says that she could hear the trauma in his voice — the result, she believes, of excessive training.

She said that steroids are a widespread problem in the SEAL program that the Navy ignores.

“Multiple independent investigations are ongoing into the circumstances surrounding seaman Kyle Mullen’s death,” the Naval Special Warfare Command said in part in response to a NewsNation request.

“It’s heartbreaking to hear you tell this story,” Mullen said. “It’s true. It all happened. And he should be alive.”

“Nobody should sign up unless they have an independent investigation,” she said. “Because they investigate themselves. And I said that’s like having a mob family investigate themselves.”

“He wanted to save lives,” she said. “And now, unfortunately, I have to make sure the world knows.”

“If your son died would you want them to get a slap on the hand? Moved to another department?” she said. “No, you’d want them held accountable.”