DOI: 10.17603/ds2-765r-hr45
title: StEER: Hurricane Otis Early Access Reconnaissance Report (EARR)
title: in StEER - Hurricane Otis

description: This project encompasses the products of StEER's Level 1 and Level 2 responses to this event: Preliminary Virtual Reconnaissance Report (PVRR) with corresponding Media Repository and the Early Access Reconnaissance Report (EARR).
description: Hurricane Otis made landfall as a Category 5 hurricane near Acapulco, Guerrero, Mexico at 6:25
UTC (12:25 AM local time) on October 25, 2023, with an estimated wind speed of over 160 mph
at landfall, surpassing Hurricane Patricia as the strongest landfalling Pacific hurricane on record.
The hurricane led to 52 reported casualties and an estimated $12-$16 billion in damage. Reports
suggest that over 98% of homes and around 80% of the hotels in Acapulco were damaged. Of
the more than 5,800 commercial establishments damaged, over 4,000 were a total loss. The
unprecedented scale of damage to single- and multi-story buildings in low-lying regions of
Acapulco included dramatic failures of glazing, cladding, and roof surfaces. These failures
extended to nearly every high-rise structure in the nearshore region.
Due to the special approvals needed for international missions, particularly given the safety
concerns, StEER delayed the deployment of its small team for a rapid survey of Acapulco,
Guerrero, Mexico until March 11 to 14, 2024. The mission focused on notable highrise failures
near the landfall area; thus, it targeted the areas along the coastline of Acapulco Bay and
neighboring Playa Diamante. Given the damage to upper stories of high-rise buildings and
equipment restrictions, unmanned aerial systems were used as the primary rapid imaging
platform to conduct free-flight surveys over specific geographies and imaging select high-rise
buildings over their full elevation. In parallel, a limited number of in-depth structural performance
assessments were conducted using StEER’s Unified Assessment mobile application in Fulcrum
platform. These efforts culminated in this Early Access Reconnaissance Report (EARR), StEER’s
second product from this event, providing an overview of Hurricane Otis, StEER’s Level 2
response, and preliminary findings based on the observations generated by its Field Assessment
Structural Team (FAST).
In general, the FAST observed: (i) extensive wind-induced failure of curtain walls and cladding
systems in buildings along the coast of Acapulco in a variety of upwind exposures including open
water, open terrain, suburban terrain, and urban canopies; (ii) widespread and complete damage
propagation to interior contents (both wind and water ingress) ensuing from the failure of curtain

walls and cladding systems, (iii) wind-induced brittle structural failures and partial collapse of low-
rise commercial buildings and other structures. Based on these observations, StEER

recommends further study in the topics of:
1. Elevated Hurricane Risk in a Changing Climate
2. Wind Speed-up Effects on Damage within Urban Canopies
3. Wind-Induced Dynamic Response of Buildings and Effects on Lateral Force Resisting
Systems (LFRS) and Components and Cladding (C&C)
4. Wind Design and Retrofit Considerations of Predominantly Seismically-Designed
Buildings
5. Risk Consistency Evaluations of Building Design Provisions for Multi-Hazard Regions
6. Wind and Seismic Design considerations for cladding, curtain wall systems and
fenestrations of mid- to high-rise structures
7. Validating observations of multi-hazard demands