Explosion and fireball seen as storm sweeps through Tennessee
A funnel cloud moving over Madison, a suburb in Tennessee, caused electrical flashes and a small explosion seen in a video shared on social media.
Parts of Tennessee were hit by tornadoes and severe storms on Saturday, and at least six people died as a result.
Buildings were reduced to rubble and communities were plunged into blackouts in the southern US state.
A funnel cloud differs from a tornado in that it doesn't touch the ground. The weather phenomenon has also been described as a "baby tornado beginning to form but never quite getting there", according to BBC meteorologist David Braine.
Read more details of the storm impact here.