Severe storms killed five people in Alabama and Tennessee overnight, and big parts of the Southeast were set to stay under a tornado watch until noon Wednesday.
In northeastern Alabama, a tornado killed at least three people early Wednesday, authorities said. Two people were later confirmed dead in Tennessee.
Photos of the deadly tornado:
Three others were also critically injured in Alabama after a day-care center was "completely destroyed" in Ider in DeKalb County, according to the National Weather Service and local sheriff's office.
Officials initially described it as a "24-hour day care" but later confirmed that it was not open when the storm hit. Its operators, who live in a nearby mobile home, sought shelter in the building. Three adults and three children from that family were later transported to hospital, DeKalb County Emergency Management director Anthony Clifton said. The three adults were listed in critical condition.
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At least 25 homes and six poultry operations were destroyed across DeKalb County, Clifton added.
The three fatalities were reported near Highway 71 in Rosalie, Alabama, located in neighboring Jackson County, the National Weather Service said.
All three victims died in one home, Jackson County Sheriff's Office Chief Deputy Rocky Harnen told NBC News.
A Baptist church and a plaza were among the 15 to 20 buildings in Rosalie that were destroyed just after midnight local time (1 a.m. ET), he added.
A roof was also blown off a motel in Guin, Alabama. Electricity lines and trees were downed throughout the area. As of 7 a.m. ET, Alabama Power reported that 4,200 customers were suffering outages, including a small number in the Birmingham area.
There were also "multiple areas with damage" in Colbert County in the northwest of Alabama, a local police official told NBC News.
RELATED: Alabama tornado damages
The band of storms stretched from the coast of Louisiana, across Mississippi and Alabama and into Georgia. New Orleans was among the cities under a tornado watch Wednesday.
Between tornado watches and heavy rain, about 10 million people from Louisiana through western North Carolina were under severe weather risk.