It depends. Some tornadoes tear across open countryside and don't affect anybody. In the worst cases a single tornado can affect tens of thousands, including dozens killed, hundreds injured, and thousands left homeless.
usually hundreds if it is a minor tornado but if it is major, usually thousands of people.
The Joplin tornado killed 158 people. The City of Joplin has a population of about 50,000 and the tornado destroyed about 1/3 of the city. So that means about 17,000 were impacted by the tornado, nearly all of whom survived.
The Waco, Texas tornado affected people in a number of ways. 114 people were killed by the tornado, meaning that many lost friends and family. In addition, 597 people were injured. Hundreds saw their homes and businesses destroyed and more suffered lesser degrees of property damage. Of the survivors many undoubtedly suffered psychological effects, as being in a building as it is struck by a tornado can be a truly terrifying experience.
The Yazoo City tornado of 2010 affected two states: Louisiana and Mississippi.
There have been many tornadoes in Arkansas. However, given the timing, you presumeably mean the tornado that struck the towns of Mayflower and Vilonia on April 27, 2014. That tornado killed 16 people.
Both. Most of the death and destruction occur during a tornado, but recovery from a particularly devastating tornado can take months or years.
People were affected in various ways. The direct impacts of the tornado killed 42 people and another three died of heart attacks from the stress of the event. More than 1,700 people were injured and an estimated 20,000 people lost their homes.
Tornadoes can easily kill, but most of the people affected by tornadoes survive.
Earth
The Greensburg, Kansas tornado of 2007 Killed 12 people and injured 63.
Yes. If you look at the statistics, the majority of people affected by a tornado will survive without serious injury.
The Waco, Texas tornado killed 114 people.