More than a dozen people were killed when a powerful storm system rumbled across the Plains and into Arkansas. Typically, people killed during tornadoes die from blunt force trauma — either being struck by flying debris or being tossed in high winds.
Following are some questions and guidance about underground basements and shelters and how people can prepare for tornadoes.
Q: What is the best way to protect yourself during a tornado?
A: Most fatalities and injuries during a tornado are caused by flying debris, so the best option is to be completely underground, either in a basement or a storm shelter. Wear sturdy shoes and do not open windows.
Q: What if you don't have a basement?
A: If you don't have a basement, go to the center of an interior room, hallway or closet on the lowest level of the building, away from windows, doors and outside walls. A general rule is to put as many walls as possible between you and the outside. Protect your head with a helmet if possible, and cover yourself with pillows and blankets.
Q: What if you are outside?
A: If you are outside, get in a vehicle and try to drive to the closest sturdy shelter. If your vehicle is hit by flying debris, pull over and park, stay in the car with seat belt on, put your head down and try to protect it. Do not try to outrun a tornado, especially in urban or congested areas. Instead, either find the closest sturdy shelter or the lowest possible area and cover your head with your hands.
Q: How do you prepare for tornadoes at night?
A: Because tornado sirens often can't be heard at night, one of the best ways to be prepared at night is to have a battery-operated weather radio that is programmed to come on when severe weather is in the area.
Q: Why are newer homes frequently built without storm shelters and basements in places where tornadoes are common?
A: The main reason that homes in the south are frequently built without basements has to do with how deep the frost level is, said Mike Hancock, who builds basements in Oklahoma. Unlike northern states, pipes, drain lines and septic tanks do not need to be more than 18 inches underground in order to avoid the frost level, Hancock said. So, it is simpler and more cost efficient to construct a new home on a traditional concrete slab foundation.
Q: How common are basements and storm shelters in Arkansas, especially in the Little Rock area?
A: Shelters are relatively common in hilly parts of Arkansas, where homes built decades ago often included concrete-lined holes dug into hillsides. Since they're only used for 20 or 30 minutes at a time, and only needed to hold a handful of people, the no-frills option was suitable for most families.
With newer construction, particularly around cities, companies market steel boxes that can double as closet space when they're not being used to hide from the storm. They're particularly suitable in homes that are built with open floor plans and without hallways that can double as an area to take shelter.
The U.S. Census Bureau reported in 1992 that 38 percent of homes in the U.S. had basements. The number had dropped to 28 percent five years ago.
In Moore, Oklahoma, where a tornado on May 20, 2013, killed 25 people and destroyed 1,100 homes, more than one-quarter of the homes are estimated to have a basement or storm shelter, according to city spokeswoman Deidre Ebrey. Of the estimated 6,000 shelters or basements in the city, about 1,100 were added after the May 20 storm. "That what woke people up," Ebrey said.
Q: The town of Vilonia was hit by a tornado three years ago. Were any shelters added in the city afterward?
A: Vilonia had community shelters at two public schools prior to the 2011 storm. Last year, it opened a third shelter at another school. The new shelter's doors are programmed to unlock automatically when the city's tornado sirens go off, according to the Faulkner County Department of Emergency Management.
Federal Emergency Management Agency, U.S. Census Bureau, Associated Press interviews.