In this appeal we address the question whether the district court erred in refusing to allow the plaintiff to introduce evidence in support of her negligence theory and in refusing to issue a negligence instruction to the jury. Because evidence of negligence was both adduced and proffered at trial and justified a negligence instruction, we hold that the district court erred. We vacate and remand the case for consideration of whether these errors were harmless.
I.
In. 1980, Josey P. Syrie, a teller at the Beaumont State Bank (now InterFirst Bank of Beaumont), was injured when the back of the teller stool on which she was sitting fell off and the chair rolled out from underneath her. The bank had purchased the chair from a local office supply store. Syrie and her husband brought the instant products liability action against Knoll International, Inc. (“Knoll”), the manufacturer of the chair, in the United States District Court for the Eastern District of Texas on the basis of diversity jurisdiction. The Syr-ies alleged that Knoll was strictly liable under Texas law for any defects in the design, manufacture, or marketing of the teller stool. They also alleged that Knoll was negligent in designing and marketing the chair, failing to warn of the hazard presented by the chair after it had been *306 sold, and failing to recall and correct the defect in the chair. Knoll answered that Syrie’s own negligence caused the accident or, alternatively, Syrie’s injuries resulted from the negligence of her employer, the bank, in maintaining the chairs. The Standard Fire Insurance Company intervened, claiming a right of subrogation to any amounts recovered by Syrie to the extent of worker’s compensation benefits and medical payments it made to Syrie.
Before trial, Knoll stipulated to the feasibility of alternative designs that would have prevented the backrest from coming loose. At trial, the district court did not permit Syrie to present evidence in support of her negligence claims. The court refused to instruct the jury regarding any of the negligence claims, ruling as a matter of law that negligence was not an issue in the case. The district court did instruct the jury on the strict liability claim and submitted the issue to the jury on a general verdict. The jury returned a verdict in favor of Knoll and the district court entered judgment accordingly. The Syries appeal.
II.
The Syries contend that the district court erred in refusing to allow evidence regarding the negligence claims and in refusing to instruct the jury on negligence. In this diversity action, we look to Texas law governing the substantive issues in this case.
Erie R.R. v. Tompkins,
To make out a strict liability cause of action, a party must establish that: (1) a product is defective; (2) the defect rendered the product unreasonably dangerous; (3) the product reached the consumer without substantial change in its condition from the time of original sale; and (4) the defective product was the producing cause of the injury to the user.
1
A defective product is one that is unreasonably dangerous, i.e., dangerous to an extent beyond that which would be contemplated by the ordinary user of the product, with the ordinary knowledge common to the community as to the product’s characteristics.
See Turner v. General Motors Corp.,
A negligence cause of action requires a different showing from a strict liability claim, even when the action is against the manufacturer.
Gonzales,
The care taken by the supplier of a product in its preparation, manufacture, or sale, is not a consideration in strict liability; this is, however, the ultimate question in a negligence action. Strict liability looks at the product itself and determines if it is defective. Negligence looks at the act of the manufacturer and determines if it exercised ordinary care in design and production.
Gonzales,
Texas has adopted Sections 395 and 398 of the Restatement (Second) of Torts as the standard of care required of a manufacturer in the design and manufacture of its products.
Gonzales,
A manufacturer who fails to exercise reasonable care in the manufacture of a chattel which, unless carefully made, he should recognize as involving an unreasonable risk of causing physical harm to those who use it for a purpose for which the manufacturer should expect it to be used and to those whom he should expect to be endangered by its probable use, is subject to liability for physical harm caused to them by its lawful use in a manner and for a purpose for which it is supplied.
Section 398, a special application of the rule in Section 395, provides:
A manufacturer of a chattel made under a plan or design which makes it dangerous for the uses for which it is manufactured is subject to liability to others whom he should expect to use the chattel or to be endangered by its probable use for physical harm caused by his failure to exercise reasonable care in the adoption of a safe plan or design.
A plaintiff must establish the following elements to sustain a negligence claim against a manufacturer: (1) the manufacturer owed a duty to the plaintiff; (2) the manufacturer breached that duty; (3) the plaintiff was injured; and (4) the breach of duty was a proximate cause of the injury.
Generally, a person who manufactures or supplies a product owes a duty of reasonable care to users of the product and to those in the foreseeable zone of danger. These suppliers must exercise reasonable care to prevent physical harm that can reasonably be foreseen to result from the use of the product for its intended purpose, and they must take reasonable care to discover the dangerous propensities of the product and to warn those who might be endangered by it.
W. Dorsaneo, Texas Litigation Guide § 320.03[1] (1984). “[I]t is a negligence concept that permits the introduction of evidence on the care exercised in the manufacturer’s selection of the design.” Special *308 Project, Texas Tort Law in Transition, 57 Tex.L.Rev. 381, 477 (1979).
The Syries argue that the district court erred in refusing to allow evidence of negligence and in refusing to instruct the jury on negligence. They contend that certain evidence that was admitted and their offer of proof would provide a sufficient basis from which the jury could conclude that the chair was negligently designed or marketed by Knoll.
Knoll responds that, negligence having not been raised, the district court could not err by excluding irrelevant testimony and suppressing inapplicable legal theories. But this contention ignores the Syries’ incorporation of a negligence claim into the pre-trial order, an incorporation that amends the previous pleadings to state a negligence claim. Fed.R.Civ.P. 16; 6 C. Wright, A. Miller & M. Kane, Federal Practice and Procedure § 1526 (1971 & Supp. 1984). Thus, Knoll is incorrect in ignoring the pre-trial order’s amendment of the pleadings to include a negligence claim.
Knoll also contends that the district court’s refusal to instruct the jury on negligence is supported by our decision in
Foster v. Ford Motor Co.,
In refusing to allow evidence regarding a better design of the chair, the district court observed:
There is no way as a matter of law that this company could be negligent if the chair was not unreasonably dangerous. Correct? The Jury is going to have to decide whether or not the chair was unreasonably dangerous. If they decide it was unreasonably dangerous, your client is going to be entitled to a verdict of this Jury . . . . I have no intention at this point of submitting the issue of negligence at all to the Jury. They are gointo make a determination of the design case as it has been filed.
If they find the chair was not unreasonably dangerous, then they couldn’t as a matter of law have been negligent. If they find it was unreasonably dangerous, then you’re entitled to a verdict regardless.
So the question of negligence is completely superfluous to this case, as I see it, and that’s the way I intend to submit it.
Record Yol. II at 195-96. The court later found as a matter of law that the Syries’ negligence claims all dealt with whether the chair was unreasonably dangerous and, thus, the case would be submitted solely as a defective design case. Id. at 286. The court explained its ruling:
[EJach area of negligence that the plaintiff sought to prove related to the product, related to the condition of the product and how and why it might have been the way it was. And there is no way that a jury could have found for the plaintiff without finding that the product was, in fact, dangerous or defective, unreasonably dangerous.
Regardless of their conduct, if it was a safe product, then any negligence on their behalf could not have been a proximate cause of any injury [Syrie] sustained, and if the product is defective and unreasonably dangerous, then regardless of their negligence, [the Syries are] entitled to a verdict, and there was no evidence offered or presented that related to conduct other than that which dovetailed into the condition of the product to *309 submit to the jury and that’s the reason I wanted the record clear.
Id. at 332. Hence, as in Foster, the district court found that the focus of the inquiry in the instant case was the condition of the product and not the conduct of Knoll in designing and manufacturing the product. In summary, the district court reasoned that the Syries could not recover under a negligence theory unless the teller stool was found to be unreasonably dangerous in which case the Syries could recover under a strict liability theory. Hence, the district court concluded, the negligence claim was superfluous and a negligence instruction unwarranted.
The rationale of the district court disregards the notion that, under Texas law, strict liability and negligence, although sharing similar and common elements, are two entirely separate theories of recovery in a products liability action. A finding of negligence is not required before a manufacturer can be held strictly liable.
Rourke,
The question, then, is whether there was evidence .or an offer of proof from which the jury could conclude that the teller stool was negligently designed or marketed by Knoll. In other words, as we posed the issue in Foster, was the issue of Knoll’s conduct in designing or marketing the chair ever raised? Based on the evidence adduced at trial and on the offer of proof, we hold that the issue of Knoll’s conduct was raised, that the proffered evidence should have been admitted and that a negligence instruction was justified. ■
Before trial, Knoll stipulated to the feasibility of design alternatives. Further, during the course of the proceedings below, Knoll stipulated that there were means of constructing the teller stool that would have made Syrie’s injury ■ impossible and yet would not have interfered with the function of the chair. Record Vol. II at 231.
James M. Williams, Knoll’s quality assurance manager, testified that, at the time the teller stool was manufactured, there were no government or industry standards which dictated features, safety or otherwise, to be incorporated into the design of the chair. He further testified that two design changes were made to the chair subsequent to the manufacture and marketing of the chair but prior to Syrie’s injury. Each of the changes — the lengthening of a bolt and the addition of a fastener — had the effect of making it more difficult for the backrest of the chair to come off. Because Knoll had stipulated to the feasibility of alternative designs that would *310 have prevented the backrest from falling off, the district court did not allow the Syries’ counsel to elicit testimony from Williams to establish that a better chair could have been designed. Nevertheless, on cross-examination, Knoll’s counsel elicited testimony from Williams to the effect that Knoll conducted a “back fatigue” test on the chair before it was marketed. The purpose of the test was to determine “whether the chair is performing as it should perform in the field.” Id. at 198-99. Williams testified that, to the company’s knowledge, Syrie’s complaint was the second associated with this particular chair model though 10,000 chairs had been produced. Williams further testified as to Knoll’s procedure for receiving consumer complaints and effecting design changes in response to those complaints.
There was testimony from James Brennan, a consulting engineer and professor of industrial engineering at Lamar University, concerning the proper method for designing a product. He testified that the design of the chair and the testing performed on the chair were inadequate, and that incorporation of safety devices, such as fasteners, guard pins, and lock washers, was a fundamental principle of design. Again, because of Knoll’s stipulation to the feasibility of alternative designs, the district court pretermitted inquiry into whether there were alternative ways of designing and producing the chair that would have prevented the backrest from falling off. Id. at 231.
The Syries’ counsel made the following offer of proof:
Dr. Brennan, if he had the opportunity, would have testified that the defendant manufacturer was negligent in the manufacture of the chair at the time of the manufacture and subsequent to the manufacture. This negligence continued up until the time of the plaintiff’s injury. That such negligence involves the negligence in design [and] in marketing and the failure, the negligent failure to recall the product or to take steps after the product had been introduced into the chain of commerce to correct the negligent design. And that such was a proxi- ■ mate cause.
Id. at 337.
It is well established that a “jury should be instructed on a legal theory only if the evidence adduced at trial is sufficient to justify such an instruction.”
Foster,
We have resolved that the refusal to permit evidence of negligence was error, as was the failure to instruct the jury on negligence. 2 The issue of harmless error was not raised before us and we have not considered it. We do not pretermit the issue from being raised below and we remand the case to the district court in order for the parties to address the issue. This will require the parties and the court to consider the theoretical and practical distinctions between a negligence action and a strict liability action under Texas law in the light of the jury’s general verdict in favor of Knoll.
III.
The Syries also claim that Knoll was negligent in failing to warn of the hazards discovered years after the chair had been manufactured and sold and in failing to recall the chairs to correct these deficiencies. The Syries cite to no case, nor has our research discovered any, which holds that the scope of a manufacturer’s duty extends so far. Under Texas law, “[a] manufacturer may be held liable for harm, if that manufacturer negligently manufactures a product which, unless care
*311
fully made, involves an unreasonable risk of causing harm to those who use it for its intended purpose and to those whom the manufacturer should expect to be endangered by its probable use.” W. Dorsaneo,
supra,
§ 320.03[2]. The failure to warn about risks posed by a product at the time it is manufactured and sold may form the basis for imposing liability on a manufacturer.
E.g., Bristol-Myers Co. v. Gonzales,
In a strict liability context, one Texas court has held that the combination of the existence and commercial availability of a superior tail rotor system to that incorporated in a line of helicopters plus the manufacturer’s knowledge that the existing rotor system was being mishandled by owners and operators constituted sufficient evidence for a jury to have found that, after the new tail rotor system became available, the mere presence of the older system rendered the helicopters unreasonably dangerous.
Bell Helicopter Co. v. Bradshaw,
In the instant action, the Syries have offered no evidence that Knoll regained any measure of control over the chairs after they were marketed in 1971. Because Texas does not impose on manufacturers the duty to warn about or to *312 recall products for which a safer design has been developed, we find that the district court did not err in refusing to instruct the jury on negligence regarding a manufacturer’s post-marketing failure to warn or recall.
IV.
For these reasons, we vacate the judgment of the district court and remand the case for proceedings consistent with this opinion. Knoll shall bear the costs of this appeal.
VACATED and REMANDED.
Notes
. In
McKisson v. Sales Affiliates, Inc.,
(1) One who sells any product in a defective condition unreasonably dangerous to the user or consumer or to his property is subject to liability for physical harm thereby caused to the ultimate user or consumer or to his property, if
(a) The seller is engaged in the business of selling such a product, and
(b) It is expected to and does reach the user or consumer without substantial change in the condition in which it is sold.
(2) The rule stated in Subsection (1) applies although
(a) The seller has exercised all possible care in the preparation and sale of his product, and
(b) The user or consumer has not bought the product from or entered into any contractual relation with the seller.
See generally Sales & Perdue, The Law of Strict Tort Liability in Texas, 14 Hous.L.Rev. 1 (1976).
. We do not agree with the Syries' further contention that the district court’s ruling in open court, though erroneous, amounted to a comment on the case that prejudiced the Syries.
. In
Bradshaw,
the court weaves negligence concepts into its discussion of the strict liability issue. Later, in addressing the negligence claim, the court states that a manufacturer has a duty to remedy defects in a product discovered after manufacture and sale only when he assumes such a duty, presumably by regaining a measure of control over the product.
