Cindy Chiu, PhD, MPH

Cindy Chiu, PhD, MPH, researcher in the Centers for Disease Control and Prevention’s National Center for Environmental Health

Cindy Chiu, PhD, MPH, is an Epidemic Intelligence Service officer at the Centers for Disease Control and Prevention’s National Center for Environmental Health. Her research focuses on morbidity and mortality related to natural and man-made disasters — including hurricanes, tornadoes and the Gulf Coast oil spill — and recommends actions to prepare and protect people before, during and after a disaster.

Featured in the June 2013 issue of the American Journal of Public Health, Chiu’s new study investigated the 2011 Alabama tornado outbreak, the third deadliest tornado event in recent U.S. history. Her study reviewed the resulting fatalities and circumstances and causes of death, and identified safety recommendations that could be used in future storms. Public Health Newswire asked Chiu about her findings and how she suggests we stay safe during tornado season.

Q. The recent deadly tornado in Oklahoma was categorized as an EF-5. Your study analyzed the impact of EF-4 and EF-5 tornadoes in 2011 that caused much destruction in Alabama and resulted in 247 fatalities. How common are devastating tornadoes like these and how do they differ from other tornadoes?
EF-4 and EF-5 tornadoes are extremely rare, but deadly. They make up less than 1 percent of all tornadoes detected, but they are responsible for 70 percent of all tornado-related deaths. Eleven EF-4 and EF-5 tornadoes struck Alabama on April 27, 2011, and they were responsible for nearly 90 percent of the deaths that occurred on that day. At wind speeds of 166-200 miles per hour for an EF-4, and over 200 mph for an EF-5, even strong structures may not be able to withstand the force.

Q. How does analyzing data from 2011 tornadoes inform how we prepare for future storms?
In our study, we examined the demographics and circumstances of death for those who died in the April 27, 2011, tornadoes in Alabama. We used death certificates and mortality data from the American Red Cross to understand where victims were during the tornado, whether they heard warnings and what protective behaviors they took. These insights help us understand whether current recommendations are working and what else we can do to prevent tornado-related deaths in the future.

Q. What findings from the analysis surprised you?
We were surprised to find that in a few households, some family members decided to seek shelter while others decided against it.Those who sought shelter survived, and those who did not died. It is important to take every warning seriously and to seek shelter immediately.

We also saw that the majority of deaths indirectly related to the tornadoes were due to power outages. People often are not aware that injuries and deaths related to power outages can happen days after tornadoes. We recommend that people prepare for extended power outages by having a storm survival kit ready.

Finally, we found that among those who received warnings, word-of-mouth warnings were the most common. We believe peer warnings can help disseminate warnings to people at risk — especially those in rural areas without sirens nearby — and motivate people to seek shelter.

Q. Did your study shed light on any ways in which implementation of tornado safety has improved? What efforts might we need to improve on?
Our study found that many persons who were warned did take protective actions, many of which were in line with recommendations from CDC and the National Oceanic and Atmospheric Administration. This tells us our public health messaging is reaching people. However, due to the severity of these tornadoes, even locations historically considered safer did not guarantee survival. Since this event, the Federal Emergency Management Agency has issued funds to build community storm shelters and individual reinforced safe rooms that are known to withstand EF-4 and EF-5 tornadoes. These efforts are encouraging, because having access to a safe shelter is critical to surviving severe tornadoes.

Q. Based on your findings, what key recommendations do you have for staying safe in the event of a tornado?
We recommend that people have a personal or family preparedness plan that identifies a safe shelter ahead of time, prepares for power outages and plans to assist older adults and vulnerable family members. It is important to review and practice these plans, so they can be executed as soon as a warning is received.

In addition, every home should have a storm survival kit with flashlights, spare batteries, a battery- powered radio, a first aid kit and enough water and non-perishable food for three days. Persons dependent on electric medical devices or refrigerated medications should have contingency plans ready.

We recommend that when people hear a warning, they should tell a friend. However, it is important to seek shelter before warning others. For more information on how to keep you and your family safe during a tornado, go to

To learn more about tornado safety from Chiu’s study, visit the American Journal of Public Health.