A deadly severe weather outbreak spawned at least one tornado in 22 states from May 15 - 21. Among the hardest hit states were Kentucky, Missouri, Oklahoma and Wisconsin.

LONDON, Ky. — The massive EF-4 tornado that killed 19 people in Kentucky last Friday tore through three counties leaving a trail of destruction in its wake. According to the National Weather Service (NWS) in Jackson, the tornado was nearly a mile wide and had peak wind speeds of 170 mph.

As a storm system approached Jackson, in Southeastern Kentucky, on May 16, a few individuals agreed to work double shifts to make sure timely warnings continued during the overnight hours, said Tom Fahy, legislative director for the National Weather Service Employees Organization.

Did alerts go out? What type of alerts did people receive? National Weather Service and others have said the Jackson office was staffed Friday night despite staffing shortages.

Areas in Laurel County that were impacted by a tornado late May 16 will be evacuated during the evening hours of May 20 ahead of more severe storms are set to move into the area, state and local officials announce during a news conference.

A deadly EF-4 tornado ravaged Laurel and Pulaski counties, but also caused damage in several other areas on May 16.

States like Kentucky, along with several that stretch from Texas to Iowa, remain at risk of severe conditions.

The National Weather Service said a “multitude of hazardous weather” would impact the U.S. over the next several days — from thunderstorms and potentially baseball-sized hail on the Plains, to heavy mountain snow in the West and dangerous heat in the South.