• Storms rip across swath of country from Texas to Michigan.
• NWS says storms “just beginning of a multi-day catastrophic”.
• Two weather-related deaths reported in McNairy, Obion counties.

The National Weather Service warned on Thursday of “generational” floods in the US South and Midwest as storms ripped across a swath of the country from Texas to Michigan, whipping up tornadoes and killing two people.

At least 19 tornadoes struck on Wednesday, destroying homes and businesses, injuring at least eight people and knocking out power to hundreds of thousands.

That was just “the beginning of a multi-day catastrophic and potentially historic heavy rainfall event”, the NWS said.

Arkansas, Missouri, Tennessee and Mississippi faced the threat of a “generational flood event” with some locations forecast to see as much as 15 inches (38 cm) of rain by the weekend, which could cause rivers to burst their banks.

The Tennessee Department of Health reported two weather-related deaths in McNairy and Obion counties. Four people were injured in Craighead County in Arkansas and four others, including one critically, were injured when a church was hit in Ballard County, Kentucky, according to local officials.

Railroad company BNSF said it had received a report of a freight train derailment near the storm-hit city of Bay in Arkansas, without specifying the cause.

Late Wednesday, Arkansas, Kentucky and Tennessee declared a state of emergency.

The National Weather Service said parts of Arkansas, Missouri, Indiana, Illinois, Ohio and Texas were under a high risk of severe thunderstorms on Thursday, warning of more tornadoes, hail and life-threatening flooding.

“The word for tonight is ‘chaotic,'” Scott Kleebauer, a NWS meteorologist, said on Wednesday. “This is a large expanse of storms migrating slowly to the east, stretching from southeast Michigan down into southeastern Arkansas.”

Missouri’s Emergency Management Agency said a tornado that hit the town of Nevada, Missouri had caused “major damage to several businesses, power poles were snapped and several (empty) train cars were flipped onto their sides…”

More than 400,000 customers had their power knocked out across the storm-hit area, according to PowerOutage.us.