https://doi.org/10.2749/newyork.2019.2172 Distributed by Structurae 1Tropicana Garage Collapse David B. Peraza, PE PrincipalEngineerExponentNewYork,NY,USAdperaza@exponent.com Mr.Perazahasover40yearsofstructuralandcivilengineeringexperience,whichhasincludeddesignandtheinvestigationofhigh‐profilecollapses.1 Abstract In2003,amajorcollapseoccurredduringconstructionofaparkinggarageattheTropicanaHotelinAtlanticCity,NewJersey.Itresultedinfourfatalities,dozensofinjuredworkers,andsignificantdelaystotheconstructionproject.Thelegalmatterwaseventuallysettledoutofcourt,reportedlyfor$100millionUSdollars. TheauthorledthestructuralinvestigationintothecollapseonbehalfoftheGeneralContractor.Theinvestigationincludednumeroussitevisits,preservationofstructuralevidence,reviewofdesigndrawingsandcontractor’sshopdrawings,structuralanalyses,andlitigationsupport.Theconcreteparkinggaragewasbeingconstructedwithaproprietarystructuralfloorsystem,whichinvolved“stay‐in‐place”precastconcreteformsthatbecamecompositewiththecast‐in‐placeconcreteslabsandwidebeams.Theinvestigationpresentedsignificantchallengesduetotheintertwineddesignresponsibilitiesforthesystem,thedifficultyofpreservingperishableevidenceduringthedemolitionoftheunstablestructure,thehigh‐profilenatureofthecollapse,andthediverseinterestsofthemanyinvolvedparties.Themattersettledoutofcourt,sotheresultsoftechnicalinvestigationsandthelessonslearnedhavenotbeenwidelydisseminatedpreviously.Thispaperwilldescribetheengineeringinvestigationandfindings,discusstherolesandresponsibilitiesofthedesignersandothers,andpresentrecommendationstoreducefuturefailuresofsimilarlyorganizedprojects.Keywords:collapse,parkinggarage,Tropicana,precastformwork,concrete2 Introduction Thestructurebeingconstructedwasaten‐story,2400carparkinggaragelocatedoverafour‐storyretailcomplex.Atthetimeofthecollapse,theparkinggaragestructurewascompletedupthroughLevelP7.ConcretewasbeingplacedonLevelP8,intheareathatcollapsed.2172