NIST National Construction Safety 

Team Investigation of Hurricane Maria

NCST Advisory Committee Meeting – June 14, 2023

Cross-Project Panel Theme 3: Infrastructure Dependencies Ken Harrison, Jennifer Helgeson, Maria Dillard
• Hurricane Maria’s infrastructure impacts included: 

• Complete electrical outage across Puerto Rico

• Severe physical damage to electric power generation, transmission and 

distribution systems, including utility-scale solar and wind power 

generation

• Cascading effects of electrical outage: water, wastewater, communications

• Near complete loss of digital communications

• Severe physical damage to tower- and building-mounted cellular 

communications equipment

• Damage to miles of fiber optic cable, impacting wireless and wireline 

communications

• Infrastructure serves as an important connection across all seven 

technical projects 

Infrastructure Dependencies Theme: Motivation

2
Hazard Characterization: 

Impact of power loss on 

measurement of wind, rainfall 

Hazard exposure of various 

infrastructure (e.g., towers, 

bridges, transmission lines)

Critical Buildings:

Infrastructure disruptions and 

performance of backup systems 

for hospitals and shelters

Emergency Communications: 

Post-storm accessibility issues for 

infrastructure reported by 

households

Morbidity and Mortality:

Transportation accessibility of 

healthcare

Lack of power and water for 

deceased

Lack of infrastructure to hospitals

Recovery of Infrastructure: 

Networks geodatabase 

Transportation events, power 

crew assignments, and aerial 

imagery for damage assessment 

Time to recover services

Recovery of Business and 

Supply Chains:

Disruption of power, water, cell, 

internet, transportation for 

businesses

Recovery of Social Functions: 

Disruption of power, water, cell, 

internet, transportation for 

schools and hospitals

Infrastructure Dependencies Theme: Integration of Data Streams

3
Hazard Characterization: 

How were hazard measurement 

systems impacted by loss of 

infrastructure?

Critical Buildings:

How did infrastructure 

disruptions affect building 

function for hospitals and 

shelters?

Emergency Communications: 

How did the loss of 

infrastructure impact emergency 

communications and 

evacuation?

Morbidity and Mortality: 

How did the loss of 

infrastructure impact mortality?

Recovery of Infrastructure:

What slowed recovery of 

infrastructure services?

Recovery of Business and 

Supply Chain:

How did infrastructure 

disruptions for businesses affect 

recovery? 

Recovery of Social Functions:

How did infrastructure 

disruptions for schools and 

hospitals affect recovery?

Infrastructure Dependencies Theme: Integration of Analysis

4
Infrastructure Dependencies – Highlighted Projects

Impacts to and Recovery of 

Infrastructure 

Morbidity and Mortality

Recovery of Business and 

Supply Chains & Recovery of 

Social Functions

5
Infrastructure Dependencies – Highlighted Projects

Impacts to and Recovery of 

Infrastructure 

Morbidity and Mortality

Recovery of Business and 

Supply Chains & Recovery of 

Social Functions

6
Infrastructure

Schools

Hospitals

Shelters

Storage and other redundancies Businesses

to maintain function with 

disruptions in inputs, e.g.,

• Power generators

• Tanks (e.g., potable water)

• Redundant service lines (e.g., 

multiple access roads)

• Infrastructure 

supports critical 

building functionality

• Buildings can endure 

temporary loss of 

infrastructure service

Role of Infrastructure

=

7
Hurricane Maria Damage to Infrastructure

Wireless comm: cell tower collapse

Collapsed tower 

Source: 2017

NOAA imagery

• Wireless: damage to cell towers

• Power: repair intensity is less in south central part of 

PR, as measured by work effort per km of distribution 

system; work effort proxied by number of PREPA crew 

assignments after HM

• Transportation: highest incidence rate on secondary 

roads in interior municipios not served by a primary 

road; for primary roads, higher incidence rate in more 

remote areas

Transportation road network: events Size ∝ km road within municipio

Shading ∝ Events per km

Primary Secondary Tertiary

Power: crew assignments per km distrib.

PRELIMINARY DATA ANALYSIS

8
• Wireless and Transportation at 1 month:

• In most municipios, more cell sites out-of-service 

than in-service 

• Nearly all primary and secondary roads are either 

fully or partially clear; tertiary road status is 

unknown

• Power at 3 months:

• Depending on region, 25 to 50%, of HM PREPA crew 

assignments occur after three months

Primary Secondary Tertiary

10/24/2017

assigned 3 to 14 months / 

assigned 0 to 14 months

(as percent)

Wireless communications:

Power: Work effort remaining 3 months out, as measured by PREPA 

crew assignments

Transportation road network: status 

PRELIMINARY DATA ANALYSIS

Recovery of Infrastructure

9
Infrastructure 

system

Supply Chain

Schools

Hospitals

Infrastructure inputs Infrastructure supported

Labor

Telecom

Shelters

Businesses

Infrastructure Recovery Dependencies 

• Interviews to reveal impediments to recovery of infrastructure services at 

municipio, regional and commonwealth level (Status: data collection in progress)

• Additional study components include wireless communications and the role of 

vegetation in infrastructure failure

Power

Transport

Water (Transportation, Power, Water)

10
Infrastructure Dependencies – Highlighted Projects

Impacts to and Recovery of 

Infrastructure 

Morbidity and Mortality

Recovery of Business and 

Supply Chains & Recovery of 

Social Functions

11
§ The verbal autopsy (VA) captures 

information about the cause of death, 

provided by a source different from 

those already available (death 

certificates, police reports, medical 

records).

§ The socio-environmental questionnaire 

(S ́E) captures the conditions that may 

affect the occurrence of the death. 

Infrastructure questions include à

§ The integrated database includes 

geospatial data from other sources that 

can support the analysis of excess 

mortality.

Infrastructure Disruption and Mortality

Was there active electricity supply 

from their public electrical utility?

How many days was he/she 

without an active electricity 

supply?

Was there a fully functioning 

electric portable generator to 

cover the electricity demand?

How many hours a day, on 

average, did the portable electric 

generator run?

12
Average Days without Power by Municipio Derived from

NASA Black Marble Days without Power Dataset

PRELIMINARY DATA ANALYSIS Source: Derived from NASA’s Black Marble 

(VNP46) Data Product

Hospitals

13
Relationship between Average Days without Power and 

Total 14 Day Deaths by Place of Death

Source: Derived from NASA’s Black Marble 

(VNP46) Data Product PRELIMINARY DATA ANALYSIS

14
Infrastructure Dependencies – Highlighted Projects

Impacts to and Recovery of 

Infrastructure 

Morbidity and Mortality

Recovery of Business and 

Supply Chains & Recovery of 

Social Functions

15
Social 

Functions 

Recovery

Business 

Recovery 

Common 

recovery time 

periods, 

physical 

impacts, nonphysical 

impacts Infrastructure 

Recovery 

Infrastructure and the Recovery of Business, 

Education and Healthcare

16
Distribution of Businesses

• Municipios selected 

within the six shaded 

regions shown below

– Four common regions 

across all projects

– Addition of Mayagüez 

and Ponce 

(concentration of 

manufacturers)

• Business sample 

selected by zip codes

• Percentage of 

businesses that 

responded displayed 

on the map

75%

2.8%

3.9%

9.8%

7% 1.5%

17
Disruptions in Infrastructure for Businesses

● Of the responding 

businesses, the vast 

majority experienced 

disruptions of multiple 

infrastructure services.

● Highlighted cells show 

the percent of 

businesses that 

experienced a loss of 

service. 

CRITICAL INFRASTRUCTURE –

DISRUPTIONS

0-No Disruption 1-Minor 

Disruption

2-Moderate 

Disruption

3-Severe 

Disruption

4-Complete/Major 

Disruption

CATEGORIES FOR ASSESSMENT

Critical Infrastructure 

Electrical Power, % of 

businesses that experience 

loss of service

0% 1% to 24% 25% to 50% 51% to 75% 76% to 100%

Water/sewer, % of businesses 

that experience loss of service 0% 1% to 24% 25% to 50% 51% to 75% 76% to 100%

Landline telephone, % of 

businesses that experience 

loss of service

0% 1% to 24% 25% to 50% 51% to 75% 76% to 100%

Internet/IT, % of businesses 

that experience loss of service 0% 1% to 24% 25% to 50% 51% to 75% 76% to 100%

Cellphone, % of businesses 

that experience loss of service 0% 1% to 24% 25% to 50% 51% to 75% 76% to 100%

PRELIMINARY DATA ANALYSIS 18
Preparedness in Infrastructure for Businesses

● Back-up systems and 

redundancies in critical 

infrastructure are 

important indicators of the 

preparedness of regions, 

which is a key factor for 

recovery.

● Highlighted cells show the 

percent of businesses that 

had a back-up for service. 

CRITICAL INFRASTRUCTURE -

PREPAREDNESS

1-Unprepared 2- Somewhat 

Prepared 3- Prepared 4-Very Prepared

CATEGORIES FOR ASSESSMENT

Back-up systems

Electrical Power, % of businesses 

that had back-up at the time of 

HM

0% to 25% 26% to 50% 51% to 75% 76% to 100%

Water/sewer, % of businesses 

that had back-up at the time of 

HM

0% to 25% 26% to 50% 51% to 75% 76% to 100%

Landline telephone, % of 

businesses had back-up at the 

time of HM

0% to 25% 26% to 50% 51% to 75% 76% to 100%

Internet/IT, % of businesses that 

had back-up at the time of HM 0% to 25% 26% to 50% 51% to 75% 76% to 100%

Cellphone, % of businesses that 

had back-up at the time of HM 0% to 25% 26% to 50% 51% to 75% 76% to 100%

PRELIMINARY DATA ANALYSIS 19
Disruptions and Preparedness in Infrastructure 

for Schools and Hospitals

● Of the responding schools and 

hospitals, the vast majority 

experienced disruptions of multiple 

infrastructure services.

● Nearly all experienced the loss of 

electrical power, telephone and 

internet; loss of water/sewer services 

impacted just over half of responding 

schools and hospitals.

● There was limited availability of 

backup systems across power and 

communications-related utilities.

Note: Outliers excluded from box plot.

20 PRELIMINARY DATA ANALYSIS
Questions?

Theme 1: Hospitals Theme 3: Infrastructure 

Dependencies

Theme 2: Sheltering

DongHun Yeo, Joseph Main, 

Judith Mitrani-Reiser

Marc Levitan, Katherine Johnson, 

Maria Dillard

Ken Harrison, Jennifer Helgeson, 

Maria Dillard