“Spalding County reports two fatalities. Officials say the severe storms tore a mobile home from its foundation and tossed it nearly 500 feet. The two victims — a male and a female — were found near the mobile home.” – MyFox Atlanta
“One of the hardest hit by overnight storms is Halifax County, where one person died and seven others have been confirmed injured. […] Her niece, 52-year-old Shirleen Howard, didn’t survive. Her mobile home flew about 50 yards, landing in the middle of the road.” – WSET-TV Virgina
“Concrete steps lead to remains of a tornado demolished mobile home in Preston, Miss., Wednesday, April 27, 2011. The home and one next to it were blown about 100 feet away into a cow pasture. Three related women died at the site.” –AP
A year ago we noted here at Texas Housers that of 479 tornado-related deaths from 2002 to 2009, 249, or 52% of the deaths, occurred in mobile homes. As of yesterday, 33 of the 51 tornado deaths this year occurred in mobile homes. (NOAA-confirmed information on the impact this morning’s storms won’t be available for several days.) A recent book, “Economic and Societal Impacts of Tornadoes,” calculates that people are 10 times more likely to die in a mobile home than in a regular house during a tornado.
Why does this happen to mobile/manufactured homes? Three factors- Anchoring, Construction, and Density. Each of these factors suggests action our society could (and should!) take to prevent these deaths in the future.
Anchoring – a mobile (or manufactured) home is built in a factory and then installed on the home site. While manufactured homes can be placed on a permanent, poured concrete foundation, they are often attached to the ground with metal straps. A recent report by the Texas Sunset Commission found that 15% of Manufactured home installations inspected in Texas had some type of ‘deviation’ from the state’s installation standards. Despite the fact that 15% (1 out of every 7!) installations had a problem, the state was successfully inspecting only about 40% of installations, and has a statutory requirement to inspect only a 25%.
Action Society Could Take: The weak link of high-wind home safety is a poorly tied-down home, and inspecting all homes is necessary to insure the integrity of home anchors.
Construction. After Hurricane Andrew destroyed 97% of the manufactured homes in its path, the wind construction standards for manufactured homes were increased. Nevertheless, the improvements focused primarily on manufactured homes installed in hurricane-prone coastal areas. Manufactured homes installed inland, where many tornado deaths occur, are built to inferior standards. On top of that, despite significant changes in conventional construction standards, (The latest wind load design standards for conventional construction, ASCE 7, was adopted in 2010.) wind standards for manufactured homes have not been updated in almost two decades and are based on ASCE standards from the late 80s. This has no prospect of changing any time soon: A HUD taskforce developing a proposal to update the wind standards for new manufactured homes has decided not to address inland standards, despite their obsolescence.
Action Society Could Take: Adopt wind-load standards for manufactured homes (both those installed inland and on the coast) equivalent to conventional homes, and regularly update the standards to reflect the latest science on wind-load and construction.
Density: An improperly installed home that fails in a high-wind event such as tornado endangers the homes around it, especially in high-density manufactured home parks. The National Hurricane Center reports: “debris from the damaged or destroyed homes will become missiles that have the potential to substantially damage other units…” In short, the density of mobile homes parks contributes to the danger of tornadoes.
Action Society Could Take: Homeowners have little leverage to ensure that their neighbors’ homes are properly installed and won’t become “missiles” in the next storm. But park owners do. Requiring park owners to perform regular assessments of the wind-stability of the anchors of homes in their park would reduce the danger to the community of a poorly installed home. Requiring community tornado shelters and audible tornado-watch warnings in large, high-density parks would also reduce this risk.
Poorly constructed housing and residential environments are magnifiers of ‘natural disasters’. As the death toll rises from these storms, remember while these storms are ‘natural’, the deaths aren’t.
We’ve just listed three things society can do to prevent them.