Deadliest U.S. Disaster: Introduction

Introduction

Tropical cyclones are organized weather systems that originate in the tropics and exhibit sustained (continuous) winds exceeding 74 mph. When tropical cyclones occur in the North Atlantic Ocean, they are referred to as hurricanes. In other regions, they may be referred to as typhoons. Each year during the late summer and early autumn hurricanes form in the subtropical Atlantic and move toward the United States. They vary considerably in terms of size, duration, impact, and intensity (Saffir-Simpson scale rating, Table 1). Although major hurricanes (Category 3 or higher) make landfall in the USA frequently (about once every two years on average), our coastlines are highly susceptible to substantial impacts when they strike.

Table 1. The Saffir-Simpson scale of hurricane intensity Click on image to enlarge it

Hurricane damage occurs in three ways: storm surge, winds, and inland flooding. The term storm surge refers to a wind-driven rise in ocean level that pushes water onshore near the point of where the hurricane makes landfall. In extreme cases, when the hurricane landfall coincides with high tide, the storm surge can be as high as 15-20 feet. Many hurricane fatalities, including most of the 6000+ fatalities that occurred in the 1900 Galveston hurricane, occur when people drown in the storm surge. In the strongest hurricanes, structures near the ocean are destroyed by the combination of the storm surge and hurricane-force winds. Although the storm surge and hurricane-force winds are usually limited to a short distance near the coast, hurricane impacts are often felt far inland as heavy rains cause inland flooding. For example, Hurricane Camille (a Category 5 hurricane at landfall in 1969) caused widespread damage along the Gulf Coast, but also claimed 113 lives in Virginia as heavy rains caused localized flooding.

The impact that a hurricane has ultimately depends not only on its physical characteristics but also on the characteristics of the region it affects. Note that although the 1900 Galveston hurricane and 2005’s Hurricane Katrina are the two deadliest hurricanes in US history, they are not the strongest to make landfall (see Table 2). Important regional characteristics include building codes, access to resources, ability to evacuate, and emergency preparedness. In the following readings we will investigate how storm characteristics and regional response both contributed to the losses that were realized with the 1900 Galveston hurricane and 2005’s Hurricane Katrina.

Table 2. The 10 most intense hurricanes (at landfall) to strike the United States since 1900. Death toll data are from the National Hurricane Center Publication “The Deadliest Atlantic Tropical Cyclones, 1492-present. Click on image to enlarge it

In this unit, we will investigate two of the most noteworthy hurricanes in US history: the 1900 Galveston hurricane and 2005’s Hurricane Katrina. Both of these storms resulted in significant loss of life. Our goal is to combine a basic understanding of hurricane characteristics with written accounts of these events to compare and contrast the characteristics in both hurricanes that lead to tragic losses of life.

Your task will be to answer the following question: Why did both hurricanes (1900 & 2005) result such a large number of deaths? To help you answer this central question, analyze the sources you were assigned and keep in mind the following questions:

What systems were in place to warn people about this hurricane? Do you think they were adequate?

What impact did this hurricane have on the city and its citizens?

Why was the city so vulnerable to the hurricane? What made it unique?

Who/what does the source blame? Why?