Wigand became nationally known as a whistleblower on February 4, 1996, when he appeared on the CBS news program 60 Minutes. He stated that Brown & Williamson had intentionally manipulated its tobacco blend with chemicals such as ammonia to increase the effect of nicotine in cigarette smoke. According to Wigand, he was subsequently harassed and received anonymous death threats.

Brown & Williamson undertook a concerted effort to discredit Wigand, which included hiring Terry Lenzner's company Investigative Group International, to produce a 500-page dossier on Wigand, which was distributed to the media. The dossier backfired, as news outlets examined the claims in it, finding many claims of misconduct to be unsubstantiated or trivial.

https://en.wikipedia.org/wiki/Jeffrey_Wigand

After being hired at the Kerr-McGee Cimarron Fuel Fabrication Site plant near Crescent, Oklahoma, in 1972, Silkwood joined the local Oil, Chemical & Atomic Workers Union and participated with a strike at the plant. After the strike ended, she was elected to the union's bargaining committee, the first woman to have such duties at the Kerr-McGee plant.[1] She was assigned to investigate health and safety issues. She discovered what she believed to be numerous violations of health regulations, including exposure of workers to contamination, faulty respiratory equipment and improper storage of samples. She believed the lack of sufficient shower facilities could increase the risk of employee contamination.[4]: 19–23

Silkwood said she had assembled documentation for her claims, including company papers. She decided to go public with this evidence, and contacted David Burnham, a New York Times journalist, who was interested in her story. On November 13, 1974, Silkwood left a union meeting at the Hub cafe in Crescent. Another attendee of that meeting later testified that Silkwood had a binder and a packet of documents with her at the cafe. Silkwood got into her Honda Civic and drove alone for Oklahoma City, about 30 miles (48 km) away, to meet with Burnham and Steve Wodka, an official of her union's national office.[6] Later that evening, Silkwood's body was found in her car, which had run off the road and struck a culvert on the east side of State Highway 74, 0.11 miles (180 m) south of the intersection with West Industrial Road (35.855233°N 97.584963°W). The car contained none of the documents she had been holding in the union meeting at the Hub cafe. She was pronounced dead at the scene. The trooper at the scene remembers that he found one or two tablets of the sedative methaqualone (Quaalude) in the car, and he remembers finding cannabis. The police report indicated that she fell asleep at the wheel. The coroner found 0.35 milligrams of methaqualone per 100 milliliters of blood at the time of her death — an amount almost twice the recommended dosage for inducing drowsiness.

Some journalists have theorized that Silkwood's car was rammed from behind by another vehicle, with the intent to cause a crash that would result in her death.[7] Skid marks from Silkwood's car were present on the road, suggesting that she was trying to get back onto the road after being pushed from behind.[4]: 99–101, 114–115

Investigators also noted damage on the rear of Silkwood's vehicle that, according to Silkwood's friends and family, had not been present before the crash. As the crash was entirely a front-end collision, it did not explain the damage to the rear of her vehicle. A microscopic examination of the rear of Silkwood's car showed paint chips that could have come only from a rear impact by another vehicle. Silkwood's family claimed to know of no collisions of any kind that Silkwood had had with the car, and that the 1974 Honda Civic she was driving was new when purchased and no insurance claims were filed on that vehicle.[4]: 114–115

Silkwood's relatives, too, confirmed that she had taken the missing documents to the union meeting and placed them on the seat beside her. According to her family, she had received several threatening telephone calls very shortly before her death. Speculation about foul play has never been substantiated.[4]: 99

https://en.wikipedia.org/wiki/Karen_Silkwood