OKLAHOMA CITY - As we head into severe weather season, a concerning study just released says a growing number of Oklahomans are vulnerable to tornadoes.

The biggest reason: mobile homes are dangerous places to be when there's a tornado. Still, more and more Oklahomans are now living in them.

When a EF-3 tornado tore through Woodward last April, six people were killed. All were in mobile homes.

According to the National Oceanic and Atmospheric Administration, one third of tornado fatalities occur in mobile homes.

But according to a study by Lloyds of London, those who live in a mobile homes are 23 more times likely to be killed by a tornado than those who are in a permanent home.

Yet, according to the Census Bureau : "ten times the amount of people lived in mobile homes in 1990 compared with 1950."

But riding out a tornado in a mobile home is a bad idea.

Oklahoma Department of Emergency management director Albert Ashwood says this is a good reminder for those who living in mobile homes to have a plan in place now.

"Make sure you have a safe area, make sure you have a place to go for you and your family in case of severe weather and tornadoes."

The survey also singles out Oklahoma, as the state which experiences the highest number of strong tornadoes per area.