Missouri has a very broad view of "causation" applicable to injury cases.  An injury must be causally connected to an event.  Missouri recognizes that multiple factors can directly contribute to cause an event or incident, and also recognizes that multiple events can directly contribute to cause a single indivisible injury or condition.

Sole Cause jury instructions are barred by the Missouri Approved Instructions (MAI) 1.03.  Instead, MAI 19.01 acknowledges that multiple factors can directly contribute to abut for causation analysis for both events and injuries, with comparison of the percentage of fault by each to be determined by the jury.  As a result, MAI 19.01 multiple cause analysis applies both in multiple cause cases, and multiple event cases as well.

In both multiple cause and multiple event cases, the verdict directing instructions are modified to eliminate the language that the defendant directly caused an injury or event, and substituted language that the defendant directly caused or contributed to cause instead.  This modification is used to acknowledge how multiple causes can combine to cause an event, as well as how multiple events can combine to cause a single condition or injury.

The case of Wagner v. Bondex International et al, 368 S.W.3d 340 (Mo. App. W.D. 2012) discussed but for causation in light of the Callahan decision:

It is likewise clear that Callahan did not mean to eliminate the possibility that two or more actors can contribute to cause a result, id, or that two causes that combine can constitute but for causation. [citation omitted]. 

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The general rule is that if a defendant is negligent and his [or her] negligence combines with that of another, or with any other independent, intervening cause, he [or she] is liable, although his [or her] negligence was not the sole negligence or the sole proximate cause, and although his [or her] negligence, without such other independent, intervening cause, would not have produced the injury.

Two different acts of negligence by two different actors (perhaps at different times) can create a single indivisible injury.  In Brickner v. Normandy Osteopathic Hospital, 687 S.W.2d 910 (Mo. App. E.D. 1985) the Court said:

Missouri law recognizes that where persons whose independent negligent acts coalesce to cause a single indivisible injury, each person may be jointly and severally liable for all the harm caused.

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Health care practitioners may become joint tortfeasors if their independent acts of malpractice combine to cause a single injury.

This language encompasses the concept that successive tortfeasors, committing different acts at different times, may find themselves joined causally as contributors to a single indivisible injury.  In Mackey v. Smith, 438 S.W.3d 465 (Mo. App. W.D. 2014) the Court explained:

In Missouri, an initial tortfeasor is generally liable to the plaintiff for both the harm he originally inflicted as well as any aggravation of the injury that is caused by the reasonably foreseeable negligence of another.

In short, the first negligent actor can be liable for the condition they caused, as well as any aggravation of that condition by a second and later negligent actor.  Again, MAI 19.01 makes provision for the contribution of both tortfeasors.

And, Missouri law is equally clear the second later actor need not actually cause a condition -- only that the second negligent actor merely aggravate or accelerate any condition that pre-existed.  Shannon v. Wal-Mart Stores, 974 S.W.2d 588 (Mo. App. W.D. 1998) holds:

Missouri follows the general rule that a person injured due to negligence of another is entitled to recover all damages proximately traceable to the original negligence, including subsequent aggravation which the law regards as a natural result of the original injury, even though some intervening agency may have contributed to the result.

By way of example, in Higby v. Wein, 996 S.W.2d 95 (Mo. App. E.D. 1999) the plaintiff injured her shoulder in December, 1995 and adhesive capsulitis resulted.  In April, 1996, plaintiff was in a second car wreck that aggravated the capsulitis.  The court specifically approved the use of the MAI 19.01 modification in pre-existing injury cases, as well as in multiple factor liability causation cases, in holding that the second negligent driver could be held liable for the final condition -- an aggravated adhesive capsulitis -- even though the second driver did not cause the initial adhesion.

As Mackey teaches, when the first negligent actor clearly causes the initial injury, and the injury is then aggravated by the second negligent actor, the first negligent actor remains liable not only for the initial injury but also for the eventual condition that resulted when the initial injury was aggravated in a second event.

As to the second incident, Shannon and Higby equally teach that, while the second negligent actor clearly did not cause the initial injury, the second incident nevertheless aggravated the initial injury.  As such, the second negligent actor remains responsible for the eventual combined condition that resulted when the initial injury was made worse by the second incident.

Chaussard v. Kansas City Southern Railway Company, 536 S.W.2d 822 (Mo. App. W.D. 1976) (Exhibit 43) and Lockwood v. Schreimann, 933 S.W.2d 856 (Mo. App. W.D. 1996) teach that both injuries may be submitted to the jury jointly.

In Chaussard, plaintiff suffered a lumbar spine injury in a railroad car collision in January, 1971.   Later that year, in November, 1971, plaintiff suffered a lumbar spine injury at work, resulting in surgery and a permanent impairment.  Plaintiff sued the railroad for the January, 1971 event and was allowed to jointly submit the damages he suffered in the November, 1971 work incident because it was the straw that broke the camel’s back.  The first tortfeasor was liable for the damages following the second work injury because:

Missouri follows the general rule that a person injured due to negligence of another is entitled to recover all damages proximately traceable to the original negligence, including subsequent aggravation which the law regards as a natural result of the original injury, even though some intervening agency may have contributed to the result.

The eventual condition after aggravation of the first injury by the second event was addressed by use of a damage instruction that joined both injuries together.

In Lockwood, plaintiff was injured in a motor vehicle collision in June, 1990.  Later, in October, 1991, plaintiff injured his back at work.  Plaintiff sued the defendant in the first car wreck and submitted both injuries (including the second work incident) as part of his damage instruction to the jury.  Quoting Chaussard, the Court approved the modified damage instruction, that the first incident contributed to the eventual condition following the second incident, because plaintiff's treating physician tied the two incidents together, saying:

The patient also had some type of work related strain/sprain that occurred; however it is unlikely that this would have happened had he not been suffering from the previous injury resulting from the MVA......

Again, when multiple causes combine to result in a single indivisible injury, the verdict directing instruction against the second negligent actor would modified by MAI 19.01 caused or contributed to cause language.

When multiple events combine to cause a single indivisible injury, the claim against the first negligent actor will see the MAI 4.01 damage instruction (instead of the verdict directing instruction) modified to submit both damages as was done in Chaussard and Lockwood.

The question of whether the claims of the plaintiff against both the first negligent actor and the second negligent actor can be joined together in a single cause of action is answered by State ex rel Nixon v. Dally, 248 S.W.3d 615 (Mo. Banc. 2008).  In Nixon, plaintiff was rear ended by Defendant Haynes and, ten months later, was rear ended again by Defendant Gardner.  Plaintiff sought to join both Haynes and Gardner in a single suit because the second accident aggravated conditions from the first accident.

When interpreting Supreme Court Rule 52.05, the Court determined that while the two collisions were discrete events, they were a series of occurrences which were related by the question common to both -- the origin of plaintiff’s injuries.  In upholding joinder of both collisions in a single case, the court made a compelling practical statement both from the standpoint of logic and judicial economics:

Were permissive joinder to be prohibited in cases of aggravated, successive injuries, separate trials would afford each defendant the opportunity to impute the bulk of liability to the other tortfeasor(s).  Joining the defendants both saves judicial resources by preventing multiple, duplicative trials and increases the ability of the jury accurately to apportion damages and liability.

As such, the plaintiffs’ claims against both negligent actors whose actions combined to cause a single indivisible injury may be joined together in a single lawsuit as if they were both joint tortfeasors.

Asserting related claims, either aggravation of a pre-existing condition or multiple events causing a single indivisible injury, require advice and action by an experienced Rolla personal injury attorney familiar with complex causation laws.

By: Joseph W. Rigler

DID YOU KNOW ? is presented by Williams, Robinson, Rigler & Buschjost, PC as a public information service only.  None of the information contained herein is intended to be taken as legal advice.  Each matter depends on unique facts which attorneys must consider in forming an opinion, and may depend on laws unique to a particular jurisdiction.  No two cases are the same.  If you want to know more about this subject, contact Williams, Robinson, Rigler & Buschjost, PC, or the attorney of your choice, and seek a formal opinion about your particular case.

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