Torts and professional liability

Contracts bind only the people who sign them. Yet engineers are regularly sued by people they never signed anything with: a contractor who relied on tender drawings, a building owner who bought the building years after it was built, a pedestrian hurt by a falling panel, a neighbor whose basement flooded. Those claims are brought in tort, the branch of private law that compensates people for wrongs that do not depend on a contract. For engineers, the most important tort by far is negligence, and this lesson is mostly about it.

We pick up the Northbridge bridge years later. The Westbrook pedestrian bridge opened in 2028. In 2033 a city inspection finds severe corrosion at several deck-to-stringer connections, and the bridge is closed for repairs costing about $650,000. The investigation points to a drainage detail on Northbridge's drawings that let water pond at the connections, coating defects at the steel fabricator's shop, a contractor who installed the drains at the wrong slope, and a city that skipped two scheduled inspections. The city sues all three. How is that claim analyzed, and who pays?

What a tort is

A tort is a civil wrong, other than a breach of contract, for which the courts award a remedy, usually damages. Torts protect interests that everyone has against everyone else: bodily safety, property, reputation, and in some circumstances financial interests. The same act can be a tort, a breach of contract, a regulatory offense and professional misconduct at once, as lesson 2 showed, and each proceeding runs on its own track.

The main torts that touch engineering work are these.

• Negligence: failing to take reasonable care, causing foreseeable harm to someone to whom a duty of care is owed. It covers design errors, careless inspections, inaccurate reports and poor supervision.
• Negligent misrepresentation: carelessly giving inaccurate information or advice that someone reasonably relies on to their cost. Geotechnical reports, feasibility studies, condition assessments and tender documents all carry this risk.
• Nuisance: unreasonable interference with a neighbor's use and enjoyment of land, such as vibration, dust, noise or drainage changes from a construction site.
• Strict liability torts, which do not require carelessness: for example the rule in Rylands v. Fletcher (1868), under which a person who brings something dangerous onto land and lets it escape is liable for the damage, and in the United States, liability for abnormally dangerous activities such as blasting.
• Fraudulent misrepresentation (deceit) and conversion are rarer in engineering but appear in disputes over false certificates and misused equipment.

The elements of negligence

A plaintiff suing in negligence must prove five things, usually on the balance of probabilities.

Duty of care. The defendant must have owed the plaintiff a duty to take care. The modern principle traces to MacPherson v. Buick Motor Co. (1916) in New York and to the English case Donoghue v. Stevenson (1932): a person who makes or does something that will foreseeably injure others if done carelessly owes those others a duty of reasonable care. American courts decide new duty questions by weighing foreseeability of harm against policy factors, and the Restatement (Third) of Torts states a general duty to exercise reasonable care when one's conduct creates a risk of physical harm. Engineers owe a duty of care to their clients, and in many situations to third parties who will foreseeably rely on or be affected by their work.

Standard of care. The defendant must have fallen below the standard the law expects. For professionals, that is the care, skill and diligence of a reasonably competent member of the profession in the same field, in similar circumstances, at the time the work was done. It is not the standard of the best engineer, and it does not require perfection. Hindsight is not the test: a design is judged against what was known and accepted practice when it was prepared. A specialist is held to the standard of a reasonable specialist. And an engineer who takes on work outside her competence is judged by the standard of someone competent to do it, which is one reason codes of ethics forbid practicing outside one's competence.

Breach. The plaintiff must show that the defendant's conduct actually fell below that standard. In professional cases this almost always requires expert evidence from other engineers about what a reasonable engineer would have done. Compliance with codes and standards is strong evidence of reasonable care but not conclusive, because codes set minimums and a reasonable engineer may need to go further when circumstances demand it. Conversely, breach of a code is strong evidence of negligence.

Causation. The breach must have caused the harm. The usual test is the but-for test: would the harm have occurred but for the defendant's negligence? Where several causes combine, courts ask whether each defendant's negligence materially contributed. The harm must also not be too remote: it must be of a kind that was reasonably foreseeable.

Damage. The plaintiff must have suffered actual loss: personal injury, property damage or, in some cases, financial loss. Negligence without damage is not actionable, which is why a design error caught by the checker before construction gives rise to no tort claim.

Liability for financial loss and misstatements

Courts are cautious about negligence claims for pure economic loss, meaning financial loss that is not the result of injury to the plaintiff's person or property. The worry is indeterminate liability: careless words or work can cause financial ripples to an unlimited number of people. Engineering is full of pure economic loss: a contractor that underbids because of an inaccurate quantity, a purchaser who overpays for a building with a hidden defect, an investor who relies on a feasibility study.

Most states apply an economic loss rule that limits tort claims for purely financial losses, especially between parties who could have protected themselves by contract, but the rule varies widely. Some states bar a contractor's negligence claim against a design professional with whom it had no contract; others allow such claims, often under section 552 of the Restatement (Second) of Torts, which makes a person who supplies false information for the guidance of others in their business transactions liable to a limited group of people the supplier intends or knows will rely on it. Many states also allow later purchasers of homes to sue builders for latent defects, under negligence or an implied warranty of habitability. Before predicting exposure on any project, engineers need advice on the law of the state where the project is located.

For practicing engineers the lesson is the same in both countries. When you prepare information that you know others will use, such as a geotechnical report, a structural condition assessment or a set of tender documents, expect that those others may sue you if it is carelessly wrong, and state the purpose, assumptions and limits of the information clearly. A well-written limitations section does not guarantee protection, but courts consider it when deciding whether reliance was reasonable.

Concurrent liability in contract and tort

Engineers who have a contract with the client usually owe duties in both contract and tort, although in many states the economic loss rule channels disputes between contracting parties into contract law. Where tort claims are allowed alongside contract claims, the rules differ: limitation periods may start at different times, damages are measured differently, and a contractual limitation of liability may not reach a tort claim unless it says so. Engineers should therefore make sure that any liability cap in their services agreement applies to claims however framed, whether in contract, tort, strict liability or otherwise.

Several defendants: apportioning fault

Construction failures rarely have a single cause, so courts must divide responsibility, and state rules differ more here than almost anywhere else. A few jurisdictions still apply contributory negligence, which bars any recovery by a plaintiff who was even slightly at fault. Most use comparative fault: under pure comparative fault, used in Missouri for example, a plaintiff's damages are reduced by its own share however large; under modified comparative fault, used in Kansas, a plaintiff whose share reaches 50 percent recovers nothing. States also differ on whether defendants are jointly and severally liable, so that the plaintiff can collect everything from one of them, or only severally liable, so that each pays its own share. Kansas has largely abolished joint and several liability. The program applies Kansas-style rules to the corrosion claim, using fault shares a court might find.

# Apportion a damages award by fault (assumed rules: modified comparative
# fault with a 50 percent bar; each defendant pays only its own share).
DAMAGES = 650_000
fault = {"Plaintiff (owner)": 0.10, "Contractor": 0.50,
         "Northbridge": 0.30, "Steel fabricator": 0.10}

own = fault["Plaintiff (owner)"]
if own >= 0.50:
    print("Plaintiff's fault is 50 percent or more: recovery barred")
else:
    print(f"Damages assessed: ${DAMAGES:,}; plaintiff's own fault {own:.0%}")
    for party, share in fault.items():
        if party.startswith("Plaintiff"):
            continue
        print(f"  {party:17} {share:4.0%} of fault -> pays ${DAMAGES * share:,.0f}")
    # With several liability only, an insolvent defendant's share is lost.
    print(f"  Contractor insolvent: plaintiff absorbs ${DAMAGES * fault['Contractor']:,.0f}")

Damages assessed: $650,000; plaintiff's own fault 10%
  Contractor         50% of fault -> pays $325,000
  Northbridge        30% of fault -> pays $195,000
  Steel fabricator   10% of fault -> pays $65,000
  Contractor insolvent: plaintiff absorbs $325,000

Look at how much the state's rules matter. Under several liability, Northbridge pays only its 30 percent share even if the contractor is insolvent, and the city absorbs the contractor's share. In a state with joint and several liability, Northbridge could end up paying most of the loss. Insurers and lawyers look first at the governing law, and firms working in several states should know which rules apply in each.

Who is liable: firm, employee or both

The engineering firm is vicariously liable for negligence committed by its employees in the course of their employment, so the client usually sues the firm. Individual engineers can also be personally liable in tort for their own negligence, and in many states plaintiffs name the engineer who sealed the drawings as well as the firm. Practicing through a corporation or limited liability company protects owners from the firm's ordinary debts but generally does not shield a professional from liability for her own negligence. Engineers should confirm that the firm's professional liability policy covers them personally, including after they leave.

Statutes of limitations and repose

Even a strong claim fails if it is filed too late. Statutes of limitations set a period, often two to five years for negligence, that usually runs from when the injury occurred or was discovered. Kansas generally allows two years for negligence claims under K.S.A. 60-513. Most states also have a construction statute of repose, which bars claims against designers and builders a fixed number of years after substantial completion of an improvement to real property, whether or not the defect has been discovered. Kansas sets a ten-year outer limit for many such claims; other states range from about four to fifteen years, and some carve out exceptions for fraud or personal injury. Engineers should keep project records at least as long as the repose period, and many keep them for the life of the structure.

Managing professional liability

The law of negligence cannot be contracted away entirely, but firms can manage it. The practical tools are the same everywhere.

• Quality management: independent checking of calculations and drawings, design reviews at key stages, document control, and written procedures for software validation. Most claims arise from ordinary errors that a checker would have caught.
• Clear scope: written agreements that define what the firm will and will not do, and written confirmation when the client declines a recommended service, such as full-time field review.
• Contract terms: liability caps that apply however a claim is framed, exclusions of consequential loss, standard-of-care clauses, and no warranties or guarantees beyond insurance.
• Communication: documenting advice, especially advice the client did not take, and stating the limits of reports in plain words.
• Insurance: professional liability insurance on a claims-made basis, kept in force or extended after a firm closes or an engineer retires; prompt notice to the insurer of circumstances that might lead to a claim.
• Records: keeping calculations, correspondence and field reports, which are usually the best evidence of reasonable care years later.