By the Numbers

70

Average number of fatalities tornadoes cause annually in the U.S.

1,500

Average number of injuries tornadoes cause annually in the U.S.

250 mph

Wind speed of strong tornadoes

30 mph

Average forward speed of strong tornadoes

40,000

Customers without power a day after the tornado in Oklahoma City on May 20, 2013

EF5

The Fujita Scale preliminary rating the Oklahoma City tornado received, giving it wind speeds of approximately 200 mph

Source:  Missouri Storm Aware, CNN