Updated

When a deadly tornado tore through the central Oklahoma city of Moore, many survivors emerged from their storm shelters to see their homes blown away.

The mayor suggested that storm shelters should perhaps be mandated for new homes. But that may be hard sell.

But not a single state currently requires storm shelters in new homes. And not even many communities do so.

Costs remain a deterrent despite the life-saving potential of personal storm shelters. So, too, does a general resistance to government mandates in politically conservative states in the nation's heartland where tornadoes are most prevalent.

Instead of a stick, Oklahoma currently offers a carrot to build storm shelters. It uses federal funds to award $2,000 rebates to residents who win a special storm-shelter lottery.