Darkness settles quickly over the small Oklahoma town of Crescent. Streetlights pop on along the two-block downtown, illuminating a cafe, the city hall and an antique shop. Around the corner, a saddle store and lumberyard have closed for the day.

Just south of downtown along State Highway 74, short rows of bungalows with big front porches fade into the sunset, and soon, the only lights shining on the highway are glaring headlights.

Dry, brown weeds stand in silhouette against wire fences along the road, and trees loom as giant shadows.

Shallow ditches grow inky black as they dip out of reach of headlights. This is where 28-year-old Karen Silkwood died, and it is where her investigation into possible nuclear misconduct broke open 30 years ago.

Like the cold, black night of Nov. 13, 1974, the mysteries of Silkwood’s death remain shrouded in darkness.

The evening had been quiet for Oklahoma Highway Patrol Trooper Rick Fagan until he got the call about Silkwood’s car accident at about 8 p.m. After six months on the job, this was just the second time he’d been the lead investigator of a fatal accident.

As he pulled up to the scene, several passersby stood on the edge of the two-lane highway, looking at the wreckage. Someone aimed headlights into the ditch.

Fagan, now a lieutenant, remembers seeing Silkwood slumped over behind the steering wheel of her 1973 white Honda Civic. The tiny car was crumpled into a concrete culvert on the east side of Highway 74, about seven miles south of Crescent.

Silkwood’s body was taken to Logan County Hospital in Guthrie, and a tow truck pulled her car from the ditch. Fagan found one or two tablets of the sedative methaqualone in the car and he remembers finding marijuana, too.

Fagan easily explained the accident: The sedative caused Silkwood to cross over the highway to the left and ram into the culvert.

Her car had traveled about 255 feet south in the ditch east of the highway before striking the north retaining wall of a bridge, Fagan wrote in his accident report. Then the car flew into the air, struck the south retaining wall and landed on the driver’s side.

Fagan came to his conclusions after interviewing several people with whom Silkwood had met before heading toward Oklahoma City.

“I had two of them the next day who told me they thought she was intoxicated and offered to drive her home,” Fagan said.

In Oklahoma City, three men were waiting for Silkwood at a hotel. Minutes and then hours ticked by after she should have arrived, and they finally got a phone call: Silkwood was dead.

Officials at the crash site told the men they believed Silkwood had fallen asleep, but Steven H. Wodka couldn’t believe it. Their meeting was too important for her to have dozed off, and Silkwood had been on the road for just a few miles.

“We were in disbelief that the Oklahoma state police were so quick to close the books on the case,” Wodka said. “That, to us, smacked that there was something else going on — that they were trying to hide something.”

Silkwood had reportedly been gathering evidence for months that her employer, Kerr-McGee Nuclear Corp., dangerously cut corners when it came to worker safety at the plutonium plant just south of Crescent.

A laboratory analyst, Silkwood belonged to the local Oil, Chemical and Atomic Workers Union, which had contacted the international union that summer about workers being exposed to plutonium, said Wodka, then a union representative from Washington, D.C.

“There wasn’t supposed to be any exposure to the workers,” he said. “They were constantly coming up hot (contaminated).”

The union’s look into exposure problems led to a study of quality-control procedures at the plant, which formed uranium and plutonium into fuel pins and pellets to be used as fuel in nuclear power plants.

Silkwood allegedly found photomicrographs — photos taken through microscopes — of defective fuel rods. The photos had been doctored to hide the defects, said Gerry Spence, attorney for Silkwood’s father, Bill Silkwood, who represented his daughter’s estate.

The night of her crash, Silkwood had planned to share the information and documents with Wodka and David Burnham, a reporter for The New York Times. Silkwood’s boyfriend, Drew Stephens, also waited for her in the Oklahoma City hotel.

That night after work, Silkwood went to a union meeting at Hub Café — now a vacant storefront in downtown Crescent — before turning her Honda down Highway 74 toward Oklahoma City. Just before she crashed, she drove over the bridge spanning the Cimarron River and passed the hill, the clusters of trees and the bend in the road that mostly concealed the Kerr-McGee plant.

Any documents she may have had disappeared. Fagan doesn’t remember seeing papers or photos — just Silkwood’s purse lying in the backseat.

Right away, the international union hired A.O. Pipkin Jr., a traffic-accident reconstructionist from Dallas. The union wouldn’t accept the highway patrol’s version of the wreck.

The day after the accident, Pipkin arrived in Crescent and immediately knew Silkwood had not fallen asleep at the wheel.

First, the steering wheel was bent in at the sides, showing Silkwood had been gripping it. If she had fallen asleep, it would have curved forward on the top, Pipkin said.

What’s more, her car ran off the left side of the road, but drivers who fall asleep often go to the right because of the slope of the road.

Additionally, Pipkin found a dent on the left side of the back bumper and a dent in the left rear fender below the bumper.

He didn’t find any object at the scene of the crash that would have caused the dents, according to his report. He also determined the dents were not caused by the car striking the culvert or the tow truck removing the car from the culvert.

Pipkin found enough circumstantial evidence to show that another vehicle hit Silkwood’s car from behind. That, by itself, or combined with possible overreaction by Silkwood, caused her car to go out of control, he wrote in his report.

“I’ll always wonder who killed Karen Silkwood,” Pipkin said.

Spence, the attorney for Silkwood’s estate, also wondered whether people in the nuclear industry could have killed Silkwood, he said. But he approached legal proceedings from a different angle. Bill Silkwood filed a lawsuit in federal district court claiming Kerr-McGee was negligent in allowing his daughter to be contaminated by plutonium, which can cause cancer and other health problems.

For three days in November 1974, Karen Silkwood tested positive for plutonium contamination — her fear for all the workers at the plant.

“She felt that the fellow workers didn’t realize what was happening to them,” Spence said. “She was doing everything she could to bring a halt to what she thought were the cover-ups of Kerr-McGee.”

On Nov. 5, Silkwood ground and polished plutonium samples using boxes with built-in gloves. Afterward, her left hand, right wrist, upper arm, neck, hair and nostrils were contaminated, according to a U.S. Supreme Court summary of the case. She was decontaminated that day and the next day, after she did paperwork in the lab.

The third day, she showed contamination when she arrived at the plant. Kerr-McGee sent a decontamination squad to her Edmond apartment, which found especially high levels of plutonium in the bathroom, the kitchen and Silkwood’s bedroom.

Kerr-McGee alleged “that Silkwood had intentionally removed the plutonium from the plant in an effort to embarrass the company,” according to the Supreme Court’s summary.

Wodka disagreed.

“Someone planted plutonium in her home, and that’s what led to her personally being contaminated,” he said.

The company sent Silkwood to Los Alamos National Laboratory in New Mexico, where a doctor found she had less than half the allowable amount of plutonium in her lungs, according to the journal Los Alamos Science.

She returned to work Nov. 13 and died that night.

The Oklahoma jury took Bill Silkwood’s side in the trial, awarding actual damages of $505,000 and punitive damages of $10 million. The 10th U.S. Circuit Court of Appeals reversed all but $5,000 in actual damages for lost property.

The U.S. Supreme Court found in favor of Silkwood but gave Kerr-McGee a chance to reassert its claims not addressed by the high court. Facing a new trial, Kerr-McGee settled the suit for $1.3 million in 1986 without admission of liability.

Silkwood’s death immediately unlocked wider investigations into the U.S. nuclear industry, starting with a story in The New York Times, Wodka said.

“I think that it was a part of a bigger issue as to whether or not the nuclear industry and the Atomic Energy Commission were being truthful about the risks involved with nuclear energy,” he said.

Silkwood’s encounter with working conditions at Kerr-McGee brought nationwide attention to the effects of radiation exposure and took the country one step closer to reforming the nuclear industry.

Silkwood’s death came almost four and a half years before equipment failed, melting about half of a reactor’s core at the Three Mile Island plant in Pennsylvania. The incident caused widespread fear of radioactive contamination, but the threat was never realized, according to the U.S. Nuclear Regulatory Commission.

For years, the country put safety second and nuclear production first, said David Michaels, assistant secretary of energy during the Clinton administration. After the Cold War ended, the country did not need to protect the nuclear industry — it needed to protect the workers, said Michaels, now a professor at George Washington University.

Four years ago, Congress passed the Energy Employees Occupational Illness Compensation Program, which Michaels designed, to pay for medical expenses for former nuclear workers with radiation-related cancer and other health problems.

“There was a wrong that needed to be righted,” he said. “There were sick workers and their families. What changed was, for the first time, we listened.”

At one time, Kerr-McGee had a test site in Cushing and plants near Crescent and in Gore involved in making nuclear fuel, said Monty Elder, spokeswoman for the Oklahoma Department of Environmental Quality.

The Crescent plant, called the Cimarron Corp., was built in 1969, and the plutonium operation there stopped in 1975. The Gore plant was closed in 1993. They constituted the state’s biggest venture into nuclear energy, Elder said.

Between 300 and 400 people worked at the Crescent plant during the time it operated, said John Christiansen, Kerr-McGee Corp.’s external communications specialist.

The company got out of the nuclear industry to focus on two core businesses: the exploration and production of oil and natural gas and the production and marketing of titanium oxide pigment, Christiansen said.

The Nuclear Regulatory Commission continues to direct cleanup of the three nuclear sites. The Crescent plant, still owned by Kerr-McGee, poses no immediate threat to people in the area, but contaminants remain and are being cleared, said Judy Duncan, a spokeswoman for the Department of Environmental Quality.

For some Crescent residents, the case Silkwood cracked open caused more harm than good.

Many residents worked for Kerr-McGee, Mayor James Lowe said.

“A lot of them thought she helped close the plant,” he said.

County Commissioner Leon Vadder doesn’t think another vehicle hit Silkwood’s car, and he thinks she smuggled plutonium from the plant, he said. Silkwood wasn’t and isn’t respected in the community, he and other residents said.

“I don’t think she ran in the same circles as the people who worked out there (at the plant),” said Kathy Roberts, whose mother worked with Silkwood.

Roberts was 14 or 15 and working as a waitress at The Hut restaurant in Guthrie when Silkwood worked at the plant. Roberts remembers Silkwood stopping by to grab food to go. The two didn’t know each other well.

After Silkwood’s death, the town buzzed with the news.

“I thought the circumstances were odd,” Roberts said, coming up with new theories about the accident on the spot during an interview at Crescent’s City Cafe.

A few miles south of Roberts’ lunch spot in downtown Crescent, a concrete culvert and a story of a young woman wrestling with the nuclear industry have spawned 30 years worth of theories about Karen Silkwood’s death.