Both of these cases will be vital to know by name on the final.

Summers v. Tice

33 Cal. 2d 80 (1948).

Summers is the plaintiff, won, defendant’s appealed.


When there is only one indication of an injury, can both negligent parties be liable when there is no clear indication as to who caused the injury?


When two defendant’s act negligently but there is only one indication of harm but we are not able to determine who caused the injury, both parties are liable.


Both parties are liable, affirmed.


Plaintiff and the two defendant’s are members of a hunting group. The two defendant’s negligently fired in the direction of the plaintiff and one of the bullets caught him near the eye.

The defendant’s argue that because there is no indication as to who caused the injury, neither can be found liable.


To accept the defendant’s view would be unjust. Both defendant’s were acting negligently resulting in the injury. Because we do not know who caused the injury, both are going to be liable. The defendants must decide between themselves how the damages will be apportioned.


Both parties commit one injury = both parties are still liable.

Additional Notes

This is a case where both defendants are negligent but we can’t determine who actually caused the injury (only one hit the plaintiff). Therefore, there is no but-for test that can be applied.

Here, we find in favor of the plaintiff because the defendants were both negligent even though we don’t know who caused the injury. Therefore, the burden of proof shifts from the plaintiff to the defendant. The defendant then needs to show that they either did not cause the injury or were not negligent. If they can’t figure out who caused it, then they will be jointly liable.

Sindell v. Abbott Laboratories

26 Cal. 3d 588 (1980).

Plaintiff, Sindell, lost and appealed.


“May a plaintiff, injured as the result of a drug administer to her mother during pregnancy, who knows the type of drug involved but cannot identify the manufacturer of the precise product, hold liable for her injuries a maker of a drug produced from an identical formula?”


Where there is an absence of evidence as to who caused the injury, their similar conduct is sufficient to shift the burden to the defendant’s to show that they were not negligent.


Defendant’s need to measure the likelihood that they were the ones who had provided the dangerous drug and to develop a percentage of how much damages they would be liable for.


Plaintiff’s mother had taken a drug (DES) to prevent a miscarriage. Later, the daughter argued that her mother taking the drug had caused the daughter to develop cancer. She could not identify the manufacturer of the drug but knew what the drug was and selected several defendant’s who produced a similar formula.


The court says that each defendant can be liable for the injuries caused to the plaintiff. Thus, the burden shifts to the defendant to show that they were not negligent. If they can’t show that they are not negligent, then they are liable for a percentage of the possibility that the drug was manufactured by them. The court distinguishes this case from other similar cases and makes this a new rule to be followed.

Additional Notes

DES was clearly the cause of the cancer that had developed in the daughters of mothers who took DES during pregnancy. The issue here is that we don’t know which manufacturer had developed the drug that caused the issue. This is because it was a generic drug that was distributed by whatever pharmacist had on hand. There are several issues with pursuing a law suit in this case.

  • First, we don’t know who manufactured the DES (over 200 manufacturers of DES) that the mother took.
  • Second, years had passed before the injury was identifiable.

Summers doesn’t apply because they knew that they had the potentially responsible parties. Hall doesn’t work because there were only a few defendants. Here, the defendant’s were in a better position to find out who the responsible party was (lots of money). Therefore, the burden shifts to the defendant to determine “market share liability”. Market share liability is that if you have a substantial share of the DES market, then you will be liable for that share. (i.e. if you have 10% of the market, then you pay for 10% of the damages).

However the issue with this is that it is hard to produce the records to determine who had the market share of a localized market. Therefore, the case kind of flopped and very few other jurisdictions have adopted the method.

Through 338 for tomorrow.


The content contained in this article may contain inaccuracies and is not intended to reflect the opinions, views, beliefs, or practices of any academic professor or publication. Instead, this content is a reflection on the author’s understanding of the law and legal practices.

Categories: 1L Fall, Torts

Will Laursen

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