She was hit by a car but that was not the cause of death. She was morbidly obese and a heavy smoker.
https://www.nbcnews.com/video/heather-heyer-s-mom-delivers-m...
You heard that right. Heather Heyer died of a heart attack.
Heather Heyer, whom the media has told us again and again was killed after being run over by a white supremacist. While that statement might be strictly true, generally people assume that when someone dies as a result of being struck by a car that the death is a direct consequence of injuries sustained due to being struck by a car.
EDIT: Note that James Fields, the driver, had a history of mental illness, he was denied his request to enlist in the US Army because of history of taking anti-psychotic medication.
The media deliberately used a 10 year old picture of Heather Heyer where she was young and beautiful and not morbidly obese to deliberately spark the outrage by creating the optics of "young beautiful girl tragically run down by an ugly white supremacist". That sells so much better than "a panicked schizophrene loses control, in the ensuing stampede a morbidly obese woman dies of heart attack".