On November 5th, 1974, she had been grinding and polishing pellets when during a regular self-check, a contamination detector read that she had been contaminated with almost 400 times the legal legit for plutonium contamination. Further testing at the plant’s Health Physics Office showed that not only did she test positive for contamination, but also her gloves did not have holes yet there was contamination leakage inside of them. She was sent home for urine and feces analysis over the next five days. The next morning, as she headed to a union negotiation meeting, Silkwood again tested positive for plutonium, although she had performed only paperwork duties that morning. She was given more intensive decontamination. On November 7, as she entered the plant, she was found to be dangerously contaminated, even expelling contaminated air from her lungs. A health physics team accompanied her back to her home and found plutonium traces on several surfaces, especially in the bathroom and the refrigerator. She said the contamination in the bathroom may have occurred when she spilled her urine sample. When the house was later stripped and decontaminated, some of her property had to be destroyed [4]. Kerr-McGee’s management accused Silkwood of contaminating herself to give the company trouble [2]. 

During this time, Silkwood was also investigating how the plant had been severely breaking federal nuclear regulations for a long time. Former department heads also confirmed that the plants regularly forced workers to continue working despite there being leaking pipes, leaking containers, spills, and defective equipment, causing frequent contamination [5]. In March and in September, the plant had to close temporarily when the company could not account for 20 kilos of missing plutonium. Kerr-McGee convinced the Atomic Energy Commission (AEC) that the nuclear material had been lost when it got stuck in some pipes while supposedly flushing the pipes with acid, but the pipes had never been flushed [5]. Silkwood began collecting evidence in a large binder, including company papers,  that the management had actually been illegally selling the plutonium, enough to make a nuclear bomb, to a plutonium smuggling ring [4]. After days of several threatening phone calls, on November 13, 1974, she arranged to meet New York Times reporter David Burnham to go over the case after work that evening. Fellow union members who had seen her that day reported that they witnessed her getting into her car with her binder of evidence and watched her driving away after she put it in the front passenger seat [2]. However, she never arrived to meet Burnham because of her instant death in a mysterious car crash. Her binder of evidence was missing from the wreckage. Investigations concluded that someone rammed into her car from behind several times, pushing her car off a cliff. An autopsy of her body indicated that not only was she highly contaminated with plutonium in many vital organs, but she had also been drugged with an excessive dosage of sleeping pills at the time of her collision [6].  

After her death, Silkwood’s relatives and former union members filed a lawsuit against KMC for company negligence, violation of civil rights, and violation of health and environmental regulations [5]. The highly controversial case was settled two years later in the Supreme Court for $1.38 million, though KMC refused to admit liability. Further investigations conducted by the AEC also later confirmed most allegations that Silkwood and the union made [7].  Various former union members and witnesses then received threatening phone calls and also were blacklisted and unable to find any work after the incidents [5].  The plant was finally shut down in 1976 owing to bankruptcy caused by negative public opinion, investor withdrawals, and fraud convictions [5].