From city-data.com: Tornado activity:
Moore-area historical tornado activity is above Oklahoma state average. It is 423% greater than the overall U.S. average.
On 5/3/1999, a category F5 (max. wind speeds 261-318 mph) tornado 8.3 miles away from the Moore city center killed 36 people and injured 583 people and caused $1000 million in damages.
On 5/8/2003, a category F4 (max. wind speeds 207-260 mph) tornado 2.5 miles away from the city center injured 134 people and caused $370 million in damages.
Read more: http://www.city-data.com/city/Moore-Oklahoma.html#ixzz2TsqhEZUI