The 2011 outbreak in Alabama was declared a federal emergency and led to improvements in the state’s tornado shelters in addition to its warning systems, experts said.

“Since then, through funds from FEMA, there has been a lot of work to put in community safe rooms to be used during storms, as well as money that has gone out through individual mitigation funds to put in tornado safe rooms in houses,” said Lisa McCormick, an expert on emergency preparedness and associate dean for public health practice at the University of Alabama at Birmingham.

McCormick said the state also worked to upgrade its outdoor warning systems so that they would be able to target county areas being impacted by incoming storms.

Experts recommend having a plan long before a tornado threat occurs, such as going to a basement, storm cellar or interior room away from windows and outside walls. People in mobile homes are encouraged to evacuate to community shelters.