What Happened to Karen Silkwood? The Lost Tapes

Fifty years after the crash that killed Karen Silkwood on a dark stretch of Oklahoma's Highway 74, a rekindled effort to get to the bottom of her untimely death has unearthed new clues that might help solve the mystery.

With the race against the clock on a case grown cold, ABC News has tracked down some remaining puzzle pieces -- from never-before-heard audio tapes and remnants of physical evidence from the scene to people who knew Silkwood and remain haunted by both her absence and the absence of definitive answers.

"Did my mother pass in a single car accident? Did she simply fall asleep at the wheel and nod off and take her own life? Or was she forced off of the road?" Silkwood's only son, Michael Meadows, told ABC News Studios' "IMPACT x Nightline: What Happened to Karen Silkwood? The Lost Tapes."

ABC News Studios' "IMPACT x Nightline: What Happened to Karen Silkwood? The Lost Tapes" begins streaming on Thursday, Dec. 5, only on Hulu.

Angry but determined, Silkwood feared she was dying from plutonium poisoning when she walked out of a diner in Crescent, Oklahoma, on Nov. 13, 1974. She was a 28-year-old mother of three, working in a factory that made the fuel to power nuclear power plants. Silkwood had become an unlikely spy for her union, trying to reveal safety and manufacturing violations that she believed could prove catastrophic. Her union handlers thought the pressure had become too much and worried Silkwood might become reluctant to proceed.

Tenacious since childhood, Silkwood wasn't one to give up. She was determined to blow the whistle on her employer, one of the nation's premier energy conglomerates, Kerr-McGee. And on the night she died, she was ready to go public. She was on her way to meet with a New York Times reporter dispatched from Washington, D.C., to dig into the story.

Shortly after 7 p.m, Silkwood left a union meeting at the Hub Café, getting into her '73 white Honda Civic for the roughly half-hour drive to a Holiday Inn in Oklahoma City, where she would also be joined by a union official. When she had not arrived by 9 p.m., the two men she was meeting knew something had to be wrong.

"She should've stayed right there, in Crescent, and [the reporter] and I should've gone up there," said Steve Wodka, Silkwood's former official with the Oil, Chemical and Atomic Workers' union. "And not have put her in the vulnerability of driving down the highway. There's no question about that."

The story of Karen Silkwood made national headlines for a time and inspired the 1983 Mike Nichols film, "Silkwood," starring Meryl Streep.

In the early 1970s, Silkwood watched as her fellow workers at a nuclear fuel production plant took home good pay while handling plutonium -- then, as some got exposed to radiation. It was an era promising the peaceful atom as a path toward American energy independence. And Silkwood's company, Kerr-McGee, then a titan of the energy industry, held sway in the corridors of power.

At the time, Kerr-McGee argued it complied with existing regulations. CEO Dean McGee would later testify they "tried to be responsive" to regulators' requests and any violations were "low level" and would "not present any problem with harm to the employees or to the public." But former union employees said complaining about safety concerns was difficult.

With mounting pressure to meet production demands, Silkwood noticed contamination incidents were cropping up. She decided to work with her union to expose safety concerns held by her and some of her fellow employees.

"There's always supposed to be a barrier between the worker and plutonium. And what was going on in this plant was that barrier was being breached," Wodka said.

Silkwood told Wodka that not only were undertrained young employees put at risk, but also that crucial parts of factory quality reports were being falsified. She began compiling a long list of radiation exposures, and she volunteered to pilfer proof of what she had alleged.

"She says, 'I'll do it,'" Wodka said, adding he told her to keep a low profile. "No one should know that you're doing this," he recalled saying.

As her investigation escalated, her physical danger did too. Over the waning months of 1974, Silkwood began to get contaminated. Her urine and stool samples would eventually test so hot that, it turned out, her kits had been intentionally spiked.

By October, Wodka was urging her to get out.

"I tell you Karen, you better get the f---- outta there," he said in a phone call shared with ABC News. "That place is gonna turn into a hellhole."

Silkwood answered, "Oh, I'll be gone. … But I'm gonna shut them down before I go."

The company would later argue she contaminated herself to embarrass the company for leverage in union negotiations. Her union handlers believed someone else might have caused her contamination, and spiked her test kits, in order to sideline her and prevent her from causing trouble for Kerr-McGee -- or perhaps from jeopardizing their jobs. The Atomic Energy Commission's investigation was not conclusive.

Five days before her death, Silkwood wrote: "I have no knowledge of what happened, but I feel the contamination is coming out from my body."

The company wanted to know how she got contaminated, too, sending her to the Los Alamos National Laboratory in New Mexico for high-tech screening two days before she died. Her results would show there was plutonium in her lungs, but that her counts were within permissible levels at the time.

Silkwood also had other worries.

"She was convinced somebody was following her," friend and fellow Kerr-McGee employee Don Gummow recalled, and she was "fearful for her safety."

ABC News Studios' "IMPACT x Nightline: What Happened to Karen Silkwood? The Lost Tapes" begins streaming on Thursday, Dec. 5, only on Hulu.

Those fears loomed on that windy night when Silkwood, seen clutching a manila folder stuffed with papers, left the diner on her way to meet with David Burnham, the Times' reporter, who had broken the stories about New York police corruption immortalized in the 1973 film "Serpico" starring Al Pacino.

Silkwood never made it there. Seven miles into her drive, police said, her car suddenly veered left across the straight two-lane road, smashing into a concrete ditch. Her crumpled car would be whisked away from the scene. Witnesses at the scene said they saw papers strewn around the crash site. But, Wodka said, the papers she was supposed to bring to the meetup were never found.

Authorities said the tire tracks indicated that Silkwood had lost both consciousness and control of the wheel, causing the crash. After all, she had been prescribed a sedative for her anxiety, with a pill bottle found in her purse. It's the version of events that Oklahoma's Highway Patrol has maintained for years.

"I would either put her probably either totally asleep or in some state of stupor, induced by the medication she was taking," Oklahoma Highway Patrol Lt. Larry Owen told ABC News in 1975. A DOJ investigation that year would surmise that there were "signs of turning toward the highway at the last moment," which if she had been passed out "would seem to support the theory that Ms. Silkwood had in fact fallen asleep and had just awakened a moment prior to hitting the south wingwall."

But that official narrative never sat right with those who knew her.

"I said, 'No, wait a minute, you don't understand, she was just on the highway for a few minutes. She couldn't have fallen asleep,'" Wodka said.

Her steering wheel, bent and broken, could indicate that Silkwood braced her arms as the impact occurred -- inconsistent with someone being unconscious at the time.

"You're normally in a very relaxed state being under a depressant type drug," Owen told ABC News in 1975.

The union decided to bring in renowned crash investigator A.O. Pipkin, whose findings contradicted the official cause of the crash.

"There's enough circumstantial evidence there to indicate that somebody may have, another vehicle may have hit the car in the rear," Pipkin said at the time.

Silkwood's saga would spur congressional inquiry, an investigation by the Atomic Energy Commission and involvement by the FBI. Her contamination would also prompt her family to sue Kerr-McGee for gross negligence, eventually settling for more than a million dollars with the company admitting no wrongdoing. It was a case that wound up before the U.S. Supreme Court -- twice.

Yet fundamental questions surrounding the car crash that killed her and how she got contaminated have gone unanswered.

In 1992, a state trooper's chance encounter prompted new probing. An attorney said he'd been told by a former Oklahoma City officer that he and three other local police officers had been working off-duty for the Kerr-McGee company and were tailing Silkwood the night she died.

"Well, he is one of the four. Said they had been drinking a little bit and they were following her and they bumped her, knocked her off the road," former Oklahoma Highway Patrol Lt. Larry Dellinger said in an interview. "Probably with no intentions necessarily of killing her, but she runs off the road and hits this big concrete abutment and kills her instantly."

"That young lady was murdered, as far as I'm concerned," Dellinger added.

Dellinger is praised as a hero in Oklahoma law enforcement for saving victims of the 1995 Oklahoma City bombing, then serving as the investigator on the state prosecution of the bombers. Before all that, Silkwood's mystery caught his attention. Dellinger began recording his findings, in tapes shared with ABC News. He said he was warned that looking too closely into Silkwood's death could be dangerous.

"At one time, I gave my tapes to one of my troopers and said, 'If anything happens to me that's kinda strange, you need to open these up and get 'em to somebody,'" he said.

Eventually, Dellinger said, he got the names of the individual officers alleged to have been in the car that night. He and said he took them to the FBI and the Oklahoma State Bureau of Investigation. But nothing came of his investigation, and the trail went cold again.

All four officers are now deceased, Dellinger said. To date, there has been no official confirmation of these allegations.

The FBI and Oklahoma City Police Department declined to comment to ABC News. The other state agencies also declined to comment.

ABC Audio's new podcast, "Radioactive: The Karen Silkwood Mystery," hosted by Boettcher and Sands, explores the secrets Silkwood was uncovering and what some say is the mystery surrounding her death.

Few shards of evidence remain from the scene of Silkwood's crash. But one had been nestled atop an Albuquerque, New Mexico, garage refrigerator for decades. Following her father's deathbed request, Pipkin's daughter saved Silkwood's rear bumper, in hopes that modern science might shed new light on what happened.

Now that bumper, along with Pipkin's original notes, the official highway patrol report and other data is fueling new scrutiny. ABC News shared the evidence and case file with Steve Irwin -- one of Pipkin's proteges, and now a sought-after crash investigator in his own right -- and hired him to re-create the crash. He presented his analysis to Silkwood's family and Pipkin's daughter over Zoom.

Irwin said he believed Silkwood was likely awake -- essentially ruling out the official cause of the crash.

"There's not evidence here that would say Ms. Silkwood was asleep all the way to that head wall," Irwin said. "Quite the opposite."

What Irwin could not prove one way or the other whether there was a second vehicle that bumped Silkwood's car off the road. "That evidence just isn't available," he said.

"I'm just glad that you said that she was awake. That means a lot," Silkwood's sister Rosemary Smith responded.

"I wish the truth would come out. I wish names would come out," Dellinger told ABC. "We can't go back. We can't bring her back. But we can vindicate her."

Of course, now five decades on, reaching a definitive answer would require those who know what happened to come forward.

"In my lifetime, I would like to know what happened," Silkwood's son Meadows said. "What harm is there in telling what you know at this point, if you know something?"

ABC News' Knez Walker, Meagan Redman, Chris Donovan, Bob Sands, Michael Boettcher, Tien Bischoff and Kaitlyn Morris contributed to this report.

"Radioactive: The Karen Silkwood Mystery" is a production by ABC Audio in collaboration with Standing Bear Entertainment and the ABC News Investigative Unit. Listen to the four-part podcast series for complete coverage.