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How To Prove Negligence In A California Personal Injury Case

September 24, 2026 · california law
How To Prove Negligence In A California Personal Injury Case

Great question, and the answer is simple. You must prove duty, breach, causation, and damages.

What does that mean?

What Is Duty Under California Law?

Duty is the legal obligation to act reasonable.

Everyone has a duty to act reasonably. See CC § 1714. It’s not reasonable to drive 30 miles over the speed limit. It’s not reasonable to leave spilled liquid on a store floor for an hour. It’s not reasonable to ignore a dead tree leaning over your neighbor’s roof. What is reasonable depends on the facts.

Whether or not a duty is owed is the start of the analysis. In most cases, the answer is always yes.

What Is Breach Under California Law?

Breach is the bad act.

Breach is the failure to act reasonably under the circumstances. It’s driving 90 mph when the speed limit is 60 mph. It’s leaving water on a grocery store floor for an hour without cleaning it up. It’s failing to take protective measures against a dead tree about to fall onto your neighbor’s property.

Duty and breach are often intertwined, but they are separate concepts. Duty is the rule; breach is the violation of the rule.

What Is Causation Under California Law?

Causation is the connection between the breach and the damages.

In California, causation must be a “substantial factor.” See CACI 430. That mean’s the breach must really have caused the damages; minor or attenduated causation is not substantial. There must be real, connective tissue between the breach and the damages.

Most personal injury causes are fought over causation. It’s a complicated topic with lots of nuance.

What Are Damages Under California Law?

Damages are the detrimental, consequential effects that flow from the breach.

Damages can be pain and suffering (non-economics) or medical bills, lost wages, impairment of earning capacity (economics). As a concept, damages are easy. But they too are fought over in personal injury cases.

Questions? Contact Me for a free consultation.

Evan Walker
About the Author

Evan Walker

La Jolla Attorney

Evan W. Walker is a La Jolla attorney who has practiced law since 2008. He has practiced law throughout California, Connecticut, and Louisiana.

Evan worked for and defended insurance companies during the first 7 years of his practice. Since 2015, he has represented people with personal injury and property damage claims and insurance disputes.

Evan's practice is devoted to serious personal injury claims and catastrophic property damage claims. Areas of focus include security claims against bars and other businesses, government tort claims, fire and flood claims, and inverse condemnation. On behalf of clients, Evan has fought insurance firms, international companies, cities, bars, and casinos.

Evan regularly shares his expertise with other attorneys by teaching courses on insurance and inverse condemnation. He has taught several continuing legal education courses to Attorney Credits, a nationwide CLE company, and ProLawCLE, another nationwide CLE company. He also contributes to various podcasts and publications.

Associations:

  • Member, State Bar of California
  • Member, San Diego Bar Association
  • Member, Consumer Attorneys of California
  • Member, Consumer Attorneys of San Diego
  • Member, La Jolla Bar Association
  • Member, La Jolla Village Merchants Association
  • Member, San Diego Chamber of Commerce

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