UPDATE:
A swarm of tornadoes tore through the U.S. midsection today, splintering homes, damaging a prison, overturning trucks and killing at least four people in the hard-hit state of Indiana.
At least one person died in the southern Indiana town of Henryville, where television images showed homes blown apart and vehicles including a school bus thrown into buildings. Three others died elsewhere in the state
Tornadoes have also touched down north of Huntsville, Alabama severely damaging a high school. Twisters also were reported in Illinois and Tennessee.
The U.S. Storm Prediction Center warned that parts of 19 states would bear the brunt of "a significant severe weather episode," the second this week.
Tornado watches were in effect in eight states, meaning the storms had a good chance of forming. Weather service radar tracked further potential tornadoes in Indiana, Illinois, North Carolina and Tennessee.
WeatherWatch.co.nz, Bloomberg and Weatherzone