Explained: Powerful tornado leaves widespread damage in Wisconsin but time of day may have saved lives

A powerful tornado touched down in northeastern Wisconsin on Monday, hollowing out homes and toppling power lines.

EF3

A rating on the Enhanced Fujita scale indicating a tornado with severe damage, one level below the most destructive EF4/EF5 categories.

National Weather Service

The U.S. government agency that tracks and reports on weather events including tornadoes.

state of emergency

An official declaration by a governor allowing expanded resources and aid for disaster response.