A powerful tornado touched down in New Orleans on Tuesday, causing heavy damage to buildings in the city and surrounding areas, officials said.
The severe weather spanned a wide swath of southeastern Louisiana.
"The storm system brought strong winds and at least six tornadoes, which caused severe damage, including multiple injuries, dozens of damaged homes and businesses, and thousands left without power," Gov. John Bel Edwards said in a statement.
Edwards declared a state of emergency for Louisiana in the wake of the storms.
Severe thunderstorms were predicted to continue Tuesday from the central Gulf Coast region to the Ohio Valley ahead of a strong cold front, according to the National Weather service.
Very large hail, strong winds and tornadoes will be possible in the lower Mississippi River Valley and central Gulf Coast states through Tuesday evening, according to the weather service.
Multiple emergency crews were responding to reports of damage in New Orleans, said Erin Burns, press secretary to Mayor Mitchell J. Landrieu.
There were reports of some heavily damaged homes and businesses in the city's east, but so far no reports of fatalities, Burns said.
More than 17,000 people in Louisiana were without power, according to utility company Entergy's outage map.
NASA's Michoud Assembly Facility in New Orleans was damaged in the storm.
Jonathan Simeral, a materials engineer at the facility, said he initially headed to a window after getting a weather warning on his phone, but then "dove into a bathroom" after his colleagues screamed that they could see the tornado approach.
"The lights went out and you could hear stuff falling from the ceiling. Debris flying, you could hear it hitting the windows," he said.
The cluster of thunderstorms will continue to be a threat for the remainder of Tuesday, CNN Meteorologist Jennifer Gray.
"This is a serious, serious situation," Gray said.