DALLAS, TX. (NBC) -- A tornado reportedly slammed into Granbury, demolishing homes and injuring an undetermined number of people.

The tornado was part of a system of severe thunderstorms that spawned several tornadoes across North Texas and dropped large hail in some areas.

The extent of the damage and injuries was not immediately clear. However, police reported the hardest hit area was the Rancho Brazos subdivision and adjoining areas along Lake Granbury.

Emergency responders were preparing for possible mass casualties in the area.