In every personal injury lawsuit, the plaintiff faces the burden of proof to demonstrate that these elements exist:
Duty
Breach
Causation
Foreseeability
Damages
Everyone owes a duty of care to the people around them, whether they're fellow drivers, bicyclists, pedestrians, retail store patrons, a doctor/patient relationship, or any other situation that relates one person to another. That means you have a duty to act or not act in a certain way in order to avoid causing harm to other people.
If a defendant breaches that duty and it causes the plaintiff's injury in a way that could've been reasonably foreseeable, the defendant could be considered negligent.