We can compare the Oklahoma City tornado with other tornadoes to see whether this increased risk holds true and to see what kind of changes have been occurring.  Since 1975, the National Weather Service has separated out tornado fatalities associated with mobile homes. Data for other fatality locations (permanent* homes, other buildings, vehicles, outdoors) are available online from the Storm Prediction Center (http://www.spc.noaa.gov/climo/), starting with 1985. The fraction of deaths occurring in mobile homes has been increasing since 1975. Using a Kendall’s tau test (Press et al. 1992), the increase is statistically significant at the 95% confidence level. From 1976 to 1980, 24% of tornado deaths were in mobile homes. That fraction increased to 34% in 1986–90 and to 50% from 1996 to 2000.