No stranger to springtime flooding due to snowmelt, residents in states like Missouri, Illinois, Arkansas and Oklahoma are now preparing for something they aren't used to seeing: potentially historic floods in winter.

Residents in several areas have already been pushed out of their homes by rising floodwaters, and the impacts are only expected to worsen in the coming days. The floods have already been responsible for at least 17 deaths in the Plains and Midwest. In Missouri, Gov. Jay Nixon activated the National Guard to support emergency personnel and protect communities affected by the floods.

Late Tuesday morning, the Mississippi River had begun to overtop levees just north of West Alton, Missouri, St. Charles County EMA reported . Officials were directing residents of West Alton to evacuate immediately. A flash flood warning issued by the National Weather Service said the floodwaters could inundate much of the area in and near West Alton. The levee breach occurred in an area about 20 miles north of St. Louis.

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Up and down the Mississippi River, one of several rivers rising rapidly across the region, crews worked quickly to prepare sandbags and check levees to ensure they were ready to lessen the effects of the flooding, however possible.

"This is probably one of the earliest (times) we've seen flooding on the Mississippi River," said Marty Pope, senior service hydrologist with the National Weather Service office in Jackson, Mississippi, during a Monday news conference with Mississippi Gov. Phil Bryant.

According to Dr. Jeff Masters of Weather Underground, the Mississippi River at St. Louis was at moderate flood stage on Monday afternoon and is forecast to crest on Wednesday at the second highest level ever observed, just five feet below the all-time record set during the disastrous flood of 1993.

Here's what we know about the flooding impacts across several states.

Missouri

Officials continued to search Tuesday for an international soldier missing from central Missouri's Fort Leonard Wood. He was with several other soldiers when their vehicle was swept off a Pulaski County road Saturday night. Four other soldiers drowned in the flooding; officials have yet to release their identities or where they are from.

According to Pulaski County Sheriff Ron Long, two others were killed in the county by flooding on Saturday night. Long has identified the two victims of the first incident as 53-year-old Ron Gray, and 50-year-old Sandra Tilley, both of Dixon.

Tuesday morning, authorities announced a stretch of Interstate 44 was closed west of Rolla in Phelps County due to the flooding, the Associated Press reported.

Near St. Louis, flooding on the Meramec River shut down a wastewater plant, causing sewage to spill directly into nearby rivers and streams, the AP also said. The public was asked to avoid contact with floodwater in the area, and the Metropolitan Sewer District of St. Louis said Tuesday it wasn't clear when the plant would start operating again.

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The flooding has taken a tragic turn, killing several people. Two of those fatalities were confirmed in Greene County on Saturday, according to emergency management. They also reported at least 103 water rescues and 198 traffic control issues.

The two Greene County victims have been identified as Steven Welton, 42, and Edward Kammerer, 60. Welton drowned in a creek when his car was washed off the road on Saturday, the Missouri Highway Patrol told the AP. Kammerer, a tow truck driver, was electrocuted by a downed power line while he attempted to retrieve a vehicle that had gone off the roadway, Springfield-Greene County Office of Emergency Management executive director Chet Hunter said.

Kevin Lee, 53, was killed in Douglas County Sunday night when he was swept away while attempting to bring cattle to higher ground, the NWS reported.

There has been one storm-related death in Dallas County, according to officials, and another death was confirmed Tuesday in Lawrence County.

Nixon declared a State of Emergency on Sunday, according to KSDK News. He was expected to visit St. Charles County on Tuesday to tour the flooded areas.

"Widespread flooding and continued rainfall are causing very dangerous conditions across much of central and southern Missouri," said Nixon in a release. “Multiple fatalities due to flash flooding have already been reported, and I urge Missourians in flood-affected areas to stay alert, avoid travel if possible and never drive into a flooded roadway. With more heavy rain expected tonight and tomorrow, state emergency management personnel will be working around the clock to keep Missourians safe.”

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Red Cross shelters were opened to house residents forced from their homes by the flooding, according to Fox 2 News.

More than 3 inches of rain fell in many areas, and the NWS reported flooded roads in parts of Franklin County. The city of Eureka, along I-44 in St. Louis County, also experienced flooding.

With 11.15 inches reported by noon Monday, the NWS said Springfield has clinched its wettest December on record, breaking a 120-year-old record.

Illinois

Flooding worsened Tuesday in the town of Alton, as water levels continued to rise along the Mississippi River.

A southern Illinois coroner says three adults and two children have drowned after the vehicle they were riding in was swept away and sank in a rain-swollen creek.

Marion County Coroner Troy Cannon says the swift moving East Fork Creek carried the car off a low-water bridge about 7:30 p.m. Saturday near the town of Patoka, about 60 miles east of St. Louis.

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The car became lodged 150 to 200 feet downstream, but shortly after the first firefighter arrived on the scene it was dislodged and sank.

Cannon says dive teams recovered the car from the water several hours later and the bodies of the victims from the car.

The names of the victims were not immediately released. Cannon says the vehicle was traveling from Kentucky to Minnesota.

Arkansas

The Pope County Sheriff's Office said a person was killed by flooding over the weekend, the first death from Goliath in Arkansas. The victim was identified as James Evan LaRue, from Dover.

Oklahoma

Rivers and streams continued their rise Tuesday in eastern parts of the state.

Southeast of Tulsa, the Illinois River near Tahlequahrose well above its banks on Monday morning, flooding everything nearby.

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No injuries have been reported yet from this flooding, but families who live nearby have either evacuated or are prepared to do so , KTUL.com reported.

"Treat this with respect. This is a dangerous event, this is a potentially life-threatening event and we want to make sure that people that takes this as seriously as it really is," Scott Pettus, Cherokee County emergency manager, told KTUL.com.

Customers of Altus Water were asked to conserve water for 24 hours on Saturday due to a power failure at Tom Steed Reservoir, according to Altus Emergency Management.

Flooding was expected to cause major problems across the state as the storm system dumped huge rainfall totals, and officials warned residents to stay home and off roadways, the Tulsa World reported. Authorities reported more accidents than usual, which they blamed on the weather , the report added. Several interstates and highways were closed by high water levels, as well.