At least one person was killed when historic rain of more than 8 inches fell on St. Louis.
Thunderstorms in Missouri developed overnight Monday through Tuesday morning, leading to widespread flash flooding that left St. Louis motorists stranded and residents fleeing their homes.
Fire Chief Dennis Jenkerson said one person had died after being pulled from a submerged vehicle. The person's identity was withheld until family members could be notified, he said at a news conference Tuesday afternoon.
About 70 people had to be rescued or assisted as rain drenched the city, Jenkerson said.
"We've had a tremendous amount of cars that have been door-deep and also roof-deep in some of these low-lying areas," he said.
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"Now we're seeing the weight of the water cause some issues with buildings. We're having some partial roof collapse," he said. "Some of the vacant buildings are also suffering from the stress of this water."
The city had recorded 8.06 inches of rainfall by early Tuesday, surpassing the previous daily record of 6.85 inches on Aug. 20, 1915, according to the National Weather Service in St. Louis.
At least six people and six dogs were rescued by boat from flooded homes, the fire department said. Firefighters responded to about 18 homes because of substantial flooding. More than a dozen people chose to shelter in place, it tweeted.
Numerous roads were also closed in metropolitan St. Louis, including parts of Interstate 70. Video showed cars stranded on the flooded interstate and firefighters rescuing drivers from their vehicles.
The rain prompted a flash flood emergency for St. Louis County and St. Louis City. Flash flood warnings continued for St. Louis, Chesterfield and University City through 9:30 a.m. local time, according to the weather service.
O'Fallon, St. Charles and St. Peters were under a flash flood warning until 12:15 p.m. local time.
In nearby Maryland Heights, residents were urged to avoid traveling during the storm.
"Many roadways in our area are flooded and closed. Other roadways are at a standstill due [to] heavy traffic since drivers are trying to figure out alternative routes," Maryland Heights police tweeted.
A state of emergency was declared, allowing state agencies to work directly with local jurisdictions.
"With record rainfall impacting the St. Louis region and the potential for additional rain and isolated thunderstorms, we want to ensure that our communities have every resource available to respond and protect Missourians," Gov. Mike Parson said in a statement.
"We urge Missourians to follow the direction of local authorities and emergency managers, never drive in floodwaters, and always use common sense to prevent injury."