Presentation on theme: "Hyatt Regency Walkway Collapse"— Presentation transcript:
1 Hyatt Regency Walkway Collapse Presentation by William J. Frey
2 Agenda Case Narrative STS Table Case Chronology Key Decision Point Ethical Issue—Responsible DesignTo Engineer is Human (Video by Petroski)Code of Ethics Issues
3 Case NarrativeOn July 17, 1981, the second and fourth story walkways of the Kansas City Hyatt Regency Hotel collapsed killing 114 people and seriously injuring an additional 200.Cause:“A deviation in the design in the way the rods connected the lower skywalk to the upper and the upper to the ceiling of the atrium was clearly described and zeroed in on as the ultimate cause of the accident.” Petroski: 86
4 Case Narrative Warning Signs Petroski The Atrium ceiling collapsed during construction; but a study carried out by an independent engineering firm found nothing wrong with the skywalkWorkers carrying loaded wheel barrows across the skywalk complained about excess vibration and swayingPetroski“After twenty months of investigation, the U.S. attorney and the Jackson County, Missouri, prosecutor announced jointly that they had found no evidence that either a federal or state crime was committed…” (TAMU Instructor Manual)However in an investigation carried out by the attorney general of Missouri…Duncan, Gillium, and GCE International Inc. were found guilty of “gross negligence, misconduct and unprofessional conduct in the practice of engineering.” (TAMU Instructor Manual)
5 Chronology (Adopted from TAMU Instructor Manual Chronology) DateEventEarly 1976Crown Center Redevelopment Corporation begins project to build Hyatt Regency HotelJuly 1976Gillum-Colaco, Inc. selected as consulting structural engineerProject enters schematic design stageSummer 1977GCE works with PBNDML architect to decide upon basic designLate 1977Bid set of structural drawings and specificationsEarly 1978Project prepared under regional building codes
6 Chronology Date Event April 4, 1978 Contract finalized between GCE and PBNDMLSpring 1978Construction beginsAugust 28, 1978Project specifications issued for construction based on AISC standards (American Institute of Steel Construction)December 1978Eldridge Construction Company , general contractor, finalizes subcontract with Havens Steel Company. “Havens agrees to fabricate and erect the atrium steel for the Hyatt project.”February 1979“Havens makes design change from a single to a double hanger rod box beam connection….” Havens claims GCE approved. GCE denies approving this.Oct 14, 1979Atrium roof collapseNovember 1979Seiden-Page investigates collapse and carries out “a thorough design check” of all elements of atrium roof. Assures owners of overall safety of newly designed roof.
7 Chronology Date Event July 1980 Construction of hotel completed 2nd and 4th story walkways collapse killing 114 and injuring 200.February 3, 1984“Missouri Board of Architects, Professional Engineers and Land Surveyors files complaint against Daniel M. Duncan, Jack D. Gillium and GCE International Inc., charginng gross negligence, incompetence, misconduct and unprofessional conduct in the practice of engineering in connection with their performance of engineering services in the design and construction of the Hyatt Regency Hotel in Kansas City, Missouri.”November 1984“Duncan, Gillium, and GCE International Inc. found guilty of gross negligence, misconduct and unprofessional conduct in the practice of engineering. Subsequently, Duncan and Gillum lost their licenses to practice engineering in the State of Missouri, and GCE had its certificate of authority as an engineering firm revoked. American Society of Civil Engineering (ASCE) adopts report that states structural engineers have full responsibility for design projects. Duncan and Gillum now practicing engineers in states other than Missouri.”
8 Physical Surroundings People, Groups, and Roles Procedures Component / ValueWalkway DesignPhysical SurroundingsPeople, Groups, and RolesProceduresLaws, Codes, StatutesInformation and Information StructuresStatics PrinciplesExperience with past designsCement FloorsRods and boltsBox beamsAtrium with 60 foot high ceiling.Three Walkways suspended from RoofLarge space below walkways on first floorHotel OwnerArchitecture, Engineering Design , Construction , andEngineering Investigating FirmsProfessional SocietiesGovernmental OfficialsHotel Design ProcessEngineers signing off on plansContracting and subcont dividing responsibilityPost Accident InvestigationEngineering CodesContract , Civil andCriminal LawRegulatory authority delegated to Professional SocietyPost accident investigationUS attorney investigationTrial by Missouri attn genBlack Box: account of case in textbooksEase of ConstructionDifficulty of constructing with original designDesigners hand off to constructersCommunication between designer and constructerSafetyStudying past failures and testing to failureEngineers approving designInvestigating firmSigning and Signing plans (licensed engineer)Codes set stdsLegal system punishes violationsElegance or BeautyCreate a “floating” walkwayWalkway to appear suspended
9 Concepts related to Safety and Risk Risk AssessmentRisk CommunicationRisk PerceptionRisk Management
10 Safety“A thing is safe if, were its risks fully known, those risks would be judged acceptable in light of settled value principles.” (Martin/Schinzinger, Engineering Ethics, 108)Safety and risk are different sides of the same coinOne is defined in terms of the other“Settled value principles” makes safety a matter of public policy. Government plays a role. So does business. Most importantly, so do members of the public
11 Public“those persons whose lack of information, technical knowledge, or time for deliberation renders them more or less vulnerable to the powers an engineer wields on behalf of his client or employer”Michael Davis. Thinking Like An EngineerThe public is in an especially vulnerable position. They stand subject to the risk. But they do not participate in the project that generates the riskThe public has the right to free and informed consent.This right is vulnerable if risk information does not get to them, if the risk information is too complicated for them to appreciate, or no provisions have been taken to include them in the collective risk acceptability (=safety) decision.
12 Risk The other side of the coin Risk and safety are correlative and defined in terms of one another“A risk is the potential that something unwanted and harmful may occur.” (MS 108)Risk has four dimensions (assessment, management, perception, and communication)Since risk is the probability of harm and probability implies uncertainty (lack of complete knowledge), the ethics of risk lies in how this uncertainty is communicated and distributed.For example, does a government regulatory agency approve a product unless it is proven harmful….Or does it withhold approval from a product until it is proven completely safe.In the first, the burden of uncertainty falls on the public exposed to risk, in the second on the manufacturer who can’t reap benefits from selling the uncertainly risky product.
13 Risk AssessmentThe scientific and exact process of determining the degree of riskAnimal BioassaysAnimals exposed to risk fact at intense level for short period of timeProjection from animal physiology to human physiology and from short term/intense exposure to long term/less intense exposureEpidemological StudiesComparison between populations exposed to risk and populations not exposed to riskSearch for significantly higher risk ratio. Three-to-one not generally significant. Six-to-one is significantEthics of RiskSince there is uncertainty in risk assessment, an ethical issue arises as to how that uncertainty is distributed
14 Risk Assessment in Engineering Fault Tree“a diagram of the possible ways in which a malfunction or accident can occur.”“enable an engineer to analyze systematically the various failure modes attendant to an engineering project”Determining why a car won’t start by considering different failure modesHarris, E., Pritchard, M., and Rabins, M. (2005). Engineering Ethics: Concepts and Cases . Thompson: 156
15 Risk Assessment in Engineering Faiure Mode“way in which a structure, mechanism, or process can function.”Event Tree Analysis“reason forward from hypothetical events to determine what might have led to the final event”Reasoning from pipe break in nuclear reactor to possible outcomes (release of radiation)Harris, E., Pritchard, M., and Rabins, M. (2005). Engineering Ethics: Concepts and Cases . Thompson: 157
16 Limitations in Risk Assessment Cannot predict all possible failure modesHuman error is also difficult to predict (See Reason in Human Error for a possible account)Probabilities assigned are largely a matter of guesswork“We can never be sure we have all of the possible initiating events….Harris, E., Pritchard, M., and Rabins, M. (2005). Engineering Ethics: Concepts and Cases . Thompson: 157-8
17 Different Kinds of Accident Normal Accidents (Perrow)Happens in tightly coupled systemsLeads to non-linear causalitySmall failure proves difficult to isolate; spreads out to create other failures; these cascade to produced catastropheComplexity of system makes it difficult to predict accident and assess riskLadd calls these “loss of control” accidentsJohn Ladd. Bhopal Article
18 Human ErrorReason treats accidents as pathogens that are latent in a complex systemWhen circumstances are right, a configuration of events creates an opportunity for the pathogen to emergeReason argues that accidents come from human cognitive procedures that usually work for the best
19 Risk CommunicationResults of risk assessment are technical and subject to different interpretationsPublic has a right to informed consent vis a vis riskTo consent to take a risk (or withhold consent) they must understand the risk and be able to make a coherent consent decisionThis raises issues in risk communicationClear communicationComprehensive communication (not leaving out anything significant)Communication that takes into account the perspective from which the public will perceive the risk
20 Risk PerceptionThe public perceives risk according to a clear perspectiveThis renders risk perception rational because predictable (to a certain extent)Factors which influence public perception of a risk’s acceptabilityVoluntarinessExpected benefitsControl over riskMinimal dread factorMinimal unknown factor
21 Risk ManagementPolitical process of determining if a certain degree of risk is acceptable according to a community’s settled value principlesValue principles are identified via a process of deliberative democracy which respect the meta-norms of reciprocity, publicity, and accountabilityCommunity’s identify small scale project for experimental analysisThese validate settled valuesThese also help to determine if larger scale action is acceptable
22 ResourcesHyatt Regency Kansas City Walkway Collapse" Online Ethics Center for Engineering 11/24/2010 National Academy of Engineering Accessed: Thursday, December 16, 2010 <Henry Petroski (1985). To Engineer is Human: The Role of Failure in Successful Design. St. Martin’s Press:The Kansas City Hyatt Regency Walkways CollapseDepartment of Philosophy and Department of Mechanical Engineering Texas A&M University NSF Grant Number DIRPhotos by Dr. Lee Lowry, Jr. at TAMU