Definition - What does Accidental Killing mean?
Accidental killing is when one party accidentally does something that causes another person to die. Accidental killings are distinguished from involuntary manslaughter in that they do not include a person doing anything unlawful that results in the death of another. They are merely accidents that happen while a person has a reasonable belief that no harm is possible from his or her actions.
Justipedia explains Accidental Killing
In many jurisdictions, accidental killings do not constitute criminal offenses. For example, if there is black ice on the road, and a driver following driving laws hits the black ice and swerves into another car, killing someone in the other car, this would likely not constitute a criminal offense. However, if the driver had been drunk, then this would change the situation and likely result in an involuntary manslaughter conviction. Trials tend to sort out the classification of the cause of death.