Deadly Wisconsin tornado upgraded to EF-3

A first look deep inside Prairie Lake Estates mobile home park in Chetek, Wisconsin. Photo by Jack Highberger / Fox 9.

The National Weather Service upgraded the classification of the deadly Wisconsin tornado to an EF-3.

Officials say the tornado tracked across Wisconsin for 83 miles, setting the record for the longest tornado in Wisconsin since at least the start of modern documentation in 1950.

The tornado started east of Clear Lake and ended west of Ogema, reaching 140 mph winds.

The twister hit a week ago, killing one person in a mobile home park in Chetek.