Accidents which are caused by the rashness or negligence of the driver give rise to criminal liability. Section 304A of the IPC covers such liability which is punishable for 2 years or fine or both. It is absolutely necessary that death or injury should be a direct result of the negligent act of the accused.
If there is a third party intervention then the prosecution case would weaken. The remote or indirect connection will not give rise to any criminal liability. For example, if a driver while talking on the cell phone hits a pedestrian, he is directly responsible for such an accident. On the other hand, when a driver collides with a building and the window sill falls on a pedestrian walking by, then such driver will not be liable under this section.
A person who is driving or riding holds the ultimate duty to control his vehicle. Such a person is prima facie guilty of negligence if his vehicle dashes into something or someone unless he has reason to explain that he did everything in his power to keep the vehicle under control but the accident was inevitable.