Long before Rick Springfield became a chart-topping rock star and one of the biggest heartthrobs of the 1980s, he found himself caught in the middle of the Vietnam War — and made a split-second decision that has haunted him ever since.

The “Jessie’s Girl” singer revealed during an appearance on the “Joe Rogan Experience” podcast that he once fired a mortar during an enemy attack and later learned it had killed someone.

Springfield, now 77, said the shocking incident happened in 1968, when his Australian band traveled to Vietnam to entertain American troops stationed in the war zone.

According to Springfield, bands could land gigs performing for soldiers as long as they had female members who reminded the troops of home.

“So as long as we had a couple of girls in the band, they would hire you, and you could tour Vietnam during the war zone,” Springfield recalled.

He said the band remained there for roughly four months.

Springfield admitted he initially viewed the trip as a chance to earn some money, but things did not exactly go according to plan.

“I thought, ‘Oh, great. We’ll make money,’” he said, explaining that the band ultimately spent much of what they earned at military stores known as PXs.

But the trip became far more serious when Springfield and his band befriended a group of soldiers and decided to spend the night with them.

That evening, the base came under attack.

Springfield recalled soldiers rushing into perimeter bunkers while he remained near the radio shack. Suddenly, he found himself helping fire mortars.

“We got attacked, and I’m throwing mortars down the freaking tube of the radio shack,” Springfield told Rogan.

“It was freaky.”

At the time, Springfield said he was young and did not fully comprehend the consequences of what he was doing.

The reality hit him the following day.

Springfield said soldiers approached him and told him one of the mortars he fired had struck someone.

“They came in the next day and said, ‘Hey, you got one. You got one,’” Springfield recalled.

That moment, he said, has remained with him for decades.

“That still has a hard place to land in me,” he admitted. “That’s really kind of the one thing I brought back with me that I couldn’t really find a place for that to land.”

Springfield described the attack as something that felt almost unreal at the time.

“It was like the movies,” he said.

Before he fired the mortar, Springfield recalled hearing radio reports about movement in the surrounding area. He said military personnel confirmed there were no friendly forces nearby.

Then someone asked him whether he wanted to fire.

“They said, ‘Hey, you want to throw some mortars down the tube?’” Springfield recalled.

For the young musician, the moment initially felt more like an action movie than real combat.

“It was John Wayne time,” he said. “As a young kid, I didn’t really understand what I was doing.”

Decades later, however, Springfield said the full weight of the moment is impossible to ignore.

“It’s hard for me to kind of face that I was responsible for the end of a life,” he said.

Springfield acknowledged that it happened during wartime and that he was not a soldier who had gone to Vietnam intending to fight.

Still, he said those facts have not erased the emotional impact.

“I didn’t really know what I was doing,” he said. “But it was pretty heavy when I think about the reality of it.”

The experience came years before Springfield would become internationally famous, scoring massive hits and starring as Dr. Noah Drake on “General Hospital.”

But despite the fame, screaming fans and decades in the spotlight, Springfield made clear that one haunting moment from Vietnam never truly left him.