NIST National Construction Safety 

Team Investigation of Hurricane Maria

NCST Advisory Committee Meeting – June 14, 2023

Cross-Project Panel Theme 2: Sheltering 

Marc Levitan, Katherine Johnson, Maria Dillard
• Preliminary reconnaissance identified issues related to evacuation and response:

• People in flood zones were urged to evacuate and move to shelters along with residents 

in certain types of structures (e.g., wood framed houses) 

• Emergency information was provided via multiple channels, by multiple sources (e.g., 

NWS, Commonwealth and local governments, media)

• Many people had to be rescued from flooding in multiple towns

• Shelter populations continued to inhabit schools months after landfall, delaying 

resumption of normal education services 

• The NCST Act mandates NIST to “...evaluate the technical aspects of procedures 

used for evacuation and emergency response” as well as to “recommend specific 

changes to building codes, standards and practices”.

• The Hurricane Maria NCST Investigation builds upon NIST’s Joplin Tornado NCST 

Investigation to inform procedures used to designate shelters as well as codes and 

standards for buildings serving as shelters.

Sheltering Theme: Motivation

2
Critical Buildings:

Damage observations for 

buildings serving as shelters

Information about shelter 

operations

Hazard Characterization: 

Hazards at shelter sites 

including peak winds, rainfall, 

flooding, landslides, surge

Emergency 

Communications: 

Decisions about evacuation 

and sheltering by households

Recovery of Social 

Functions:

Physical impacts to building 

and infrastructure

Hazards experienced at 

location

Morbidity and Mortality:

Location of deaths (home or 

other)

Accessibility issues for those 

who sought to leave home

Sheltering Theme: Integration of Data Streams

3
Critical Buildings:

How did buildings serving as 

shelters perform? 

How were shelter functions 

and operations affected?

Hazard Characterization:

What were the hazard 

conditions at the shelter sites?

Emergency 

Communications:

Who decided to seek shelter? 

What messages were provided 

about sheltering? 

Recovery of Social 

Functions:

What were the physical 

impacts to schools serving as 

shelters?

Morbidity and Mortality: 

Where did deaths occur? 

Where did people take refuge?

Sheltering Theme: Integration of Analysis

4
Sheltering Theme: Highlighted Projects

Emergency Communications

Critical Buildings

Recovery of Social Functions

5
Sheltering Theme: Highlighted Projects

Emergency Communications

Critical Buildings

Recovery of Social Functions

6
Pre-Storm Messaging About Sheltering

• Estimates (for Ponce): 11k in flood-prone areas; 4k will seek refuge in state shelters [PR, Sep. 18]

• First option should be to take refuge in the home of family or friends [PR, Sep. 19]

• Citizens refusing relocation to a shelter had to “sign a document” [El Vocero, Sep. 20]

• Encouraging evacuation to shelters; noting capacities and number of shelters [Sep. 17]

• Lists of shelters circulating and messages encouraging people to know their zones and evacuate 

to the appropriate places [Sep. 19]

• No more beds or cots available and people are sleeping on the ground [Sep. 19]

• If evacuating or relocating to a shelter, leave early before weather conditions become 

hazardous [Sep. 18]

• If you have doubts about whether you will be in a flooded area or in danger of mudslides, you 

should seek shelter from Hurricane Maria early—before winds and rains commence. [Sep. 19]

• Particularly dangerous situation—seek higher level within the shelter now! [Sep. 20]

Twitter

7
Insight on Shelter Population Trends

133 are from repatriates from 

neighboring islands, 51 from 

Canóvanas and 8 from Vieques 

(192)

In Salinas there are 27 

refugees, in Ponce 104, in the 

Convention Center 121, and in 

Canóvanas 50 (302)

As of 5:00 AM, there are 

11,229 refugees and 580 pets

As of 2:06 AM, there are 7,144 

refugees and 288 pets in 146 

shelters

As of 8:00 PM, there are 4,422 

refugees and 105 pets

Department of Housing 

reported there are 373 

people in 15 of the 500 

shelters enabled by the State 

As of 7:00 AM, there are 299

refugees in Puerto Rico, and that 

number will rise significantly

As of 12:35 PM, there are 192

refugees remaining after the 

passage of Hurricane Irma

Twitter

Sep. 17

Sep. 19

Sep. 20

Sep. 17

Sep. 19

8
• National Hurricane Center and National Weather Service reported 

messaging targeting threat from hazards (wind, rain, flooding, etc.); 

emphasizing seriousness of threat; being an aid to local decisionmaking

• Media distributed messages about shelter locations, instructing people 

to find strong shelters

• Mayors and local government representatives emphasized evacuation 

for people in deficient structures and for those with health care needs; 

use of civil servants to inform and promote evacuation; transportation 

provided to some; and also reported insufficiencies with shelter 

facilities and supplies (power, water, beds, sanitation, etc.)

Shelter Related Content from IP interviews

PRELIMINARY DATA ANALYSIS

9
Evacuation Behavior of Survey Respondents

• A majority of sampled 

households reported they did 

not evacuate

• Most evacuees sought refuge at 

the home of a friend, relative, or 

neighbor

• 11% of evacuating respondents 

went to an emergency shelter

• Those that evacuated were asked 

about where they sought shelter 

(see pie chart)

86%

11%

PRELIMINARY DATA ANALYSIS

10
Sheltering Theme: Highlighted Projects

Emergency Communications

Critical Buildings

Recovery of Social Functions

11
Shelter Damage Observations

• Common themes at 5 selected shelter facilities: 

(preliminary observations from Phase 1 evaluations)

− Water intrusion and damage to building contents 

reported for all but one of the buildings

− Minor exterior wall damage was reported for most of 

the buildings

− Roof covering damage

− Broken/damaged windows

− Electrical damage (damage to AC units, electrical panels) 

• Phase 2 site visits and interviews are underway

Credit: GIC/Vexcel

Phase 1: Initial document 

collection and review

Phase 2: Interviews, site visits, 

additional document review

12
Estimation of Shelter Building Damage States

• Building Damage States 

estimated using Phase I 

evaluations

• To allow for comparison, 

NIST developed a damage 

state matrix to be applied 

across projects to 

hospitals, schools and 

businesses

• The damage state 

descriptions were 

informed by FEMA’s Hazus

and other literature

• Example matrix for one 

shelter building shown

0- None or Very

Minor

1- Minor 2- Moderate 3- Severe

4-Complete

Destruction

Don't Know

Damage to Roof Cover,

% of roof area

0% (no damage) to

2%

3% to 15% 16% to 50%

51% to 100%

(complete loss)

--- DK

Damage or Loss of Roof

Decking and/or Roof

Structure, % of roof

area

0% (No damage) 0% (No damage) 1% to 10% 11% to 25%

26% to 100%

(complete loss)

DK

Broken Windows and

Doors, amount or %

None Few Many (up to 50%)

Most or all (51% to

100%)

DK

Damage to Exterior

Walls

Little or no visible

damage

Marks or dents or

cracks requiring

painting or patching

for repair

Partial failure of 1

wall

Failure of 1 wall

Failure of more than

1 wall

DK

Damage to Interior

Finishes, Contents, and

Mechanical and

Electrical Systems

None Minor Moderate Severe Complete DK

% of building that had

significant water

intrusion

None 1% to 10% 11% to 25% 26% to 50%

(51% to 100%)

see note above

DK

CATEGORIES FOR ASSESSMENT

Building Components

DAMAGE DESCRIPTIONS

PRELIMINARY DATA ANALYSIS 13
Shelter Functionality and Operations 

Common themes at some of the selected shelter facilities: 

(preliminary observations from Phase 1 evaluations)

• Overcapacity

• Prolonged duration of 

occupancy

• Impacts to resumption 

of normal function and 

operation of the facilities 

used as shelters

Image Credit: GIC/Vexcel

(annotation by NIST)

Image Credit: GIC/Vexcel

(annotation by NIST)

14
Shelter Functionality and Operations 

• Flooding reported in 

designated shelter areas

• During the storm, 

shelter occupants were 

required to be relocated 

to other areas in the 

facility

“I thought my heart was going to stop ... It was

terrible: I was nervous, anguished, praying. A meter

from where I was, a part of the ceiling fell. From there,

they evacuated us to the bathroom, but there the

dripping started, and they also took us out of there

because it was no longer safe ... The coliseum lamps

fell. Everything was dreadful, as if it was shaking. The

power went out, we were left without communication.

Then the water started to come in and people started

to get alarmed. At the end, the water rose up to our

ankles ...”

Carolina Cardozo 

Shelter Occupant at Humacao Arena 

As told to Julio Alvarado, EFE, 

published on Vanguardia.com on September 25, 2017

Common themes at 

selected shelter facilities: 

(preliminary observations)

15
Sheltering Theme: Highlighted Projects

Emergency Communications

Critical Buildings

Recovery of Social Functions

16
Understanding the Performance of Schools

Critical Buildings Project 

Explaining Building Performance

• Hazard exposure

• Building design and codes

• Structural and nonstructural 

damage

• Damage mechanisms

• Resources

• Resilience characteristics

• Physical and non-physical 

impacts of the hurricane

• Hazard exposure

17

Recovery of Social Functions Project 

Explaining Recovery of Social Functions

17
Differences in Hazard Exposure for Schools

Municipalities with schools that responded to the Recovery of Social Functions Project 

Wave 1 Survey as shown in blue (NIST Study Regions shown in red). These schools will 

inform a broader understanding of building impacts and performance across Puerto Rico. 18
Estimation of School Building Damage States

Physical Impacts to Schools

• Most schools reported that 

their campus suffered physical 

damage due to Hurricane 

Maria.

• Just under half experienced 

damage severe enough to 

cause complete closure.

• ~15% of schools that 

responded served as shelters.

• Highlighted cells show modal 

response from preliminary 

analysis.

PRELIMINARY DATA ANALYSIS

19
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