3. Thelma Todd’s Carbon Monoxide Poisoning
Todd was an actress during the ’20s and ’30s, and appeared in Marx Brothers classics like Monkey Business. On December 16, 1935, she was found dead in her car of carbon monoxide poisoning. Although her death was determined to be either accidental or a result of suicide (though she had bruises around her throat, a broken nose, and cracked ribs), there are some who believe she was murdered. Conspiracists point to the fact that on the night of her death, she attended a party in Hollywood where she was overseen having an unpleasant exchange with her ex-husband, Pat DiCicco.
There were also reports at the time that her lover, director Roland West, had locked her out, causing her to seek warmth in a car and to accidentally die of carbon monoxide poisoning. The reason she got into her car that night remains a lingering mystery.