The governor of Michigan declared a state of emergency Tuesday night after rapidly rising waters crashed through two dams and forced thousands to evacuate.
Officials with the city of Midland warned residents that the Edenville Dam, along the Tittabawassee River, failed around 5:45 p.m., and that the Sandord Dam began to overflow around 6:50 p.m.
Since Monday, storms have produced more than 8 inches of rain that overflowed the dams and caused downstream flooding in Midland County. Sea Cord and Smallwood dams were experiencing high water flow on Wednesday and being closely monitored.
Gov. Gretchen Whitmer said at a press conference on Wednesday that damage to the dams has been a "known problem for a while."
"This incredible damage requires that we hold people responsible, and we are pursuing every line of legal recourse that we can," Whitmer added.
Midland City Manager Brad Kaye said flood heights are expected to be up to 5 feet higher than the last major flood, in 1986.
"In the 1986 flood, it was considered a 100-year flood," Kaye said. "Current flood is predicted to be the equivalent of a 500-year flood."
A "500-year flood" means there's a 0.002% chance -- 1 in 500 -- of it occurring in a given year, according to the United States Geological Survey.
Whitmer said on Wednesday that waters may be at their highest around 8 p.m.
"We do know that the water is continuing to rise, allbeit at a slower pace, but that's why we have got to continue to take this seriously," she added.
The National Weather Service on Tuesday evening urged anyone near the river to seek higher ground following "castastrophic dam failures" at the Edenville Dam, which is about 140 miles north of Detroit, and the Sanford Dam, the Associated Press reported.
About 130 members of the Michigan National Guard were deployed early Wednesday to help evacuate citizens and assist emergency planners with logistics. Midland County has over 83,000 residents, according to the U.S. Census.
Shelter locations are in Colman High School, Bullet Creek, Midland High School, North Midland Family Center and West Midland Family Center, said Midland County Board Chair Mark Bone.
President Donald Trump tweeted on Wednesday that his team is "closely monitoring" the floods and that FEMA would be assisting.
Kaye said local water systems are potentially at risk, and hospitals are major concern.
However, MidMichigan Medical Center-Midland said the facility isn't planning to evacuate just yet.
"We have been working alongside local agencies, watching closely the rapid changes that have been occurring due to the flooding," the hospital said in a statement. "We have transferred a few patients that were identified by their physician. ... We continue to monitor the situation as it evolves."
This report was featured in the Friday, May 22, 2020, episode of “Start Here,” ABC News’ daily news podcast.
"Start Here" offers a straightforward look at the day's top stories in 20 minutes. Listen for free every weekday on Apple Podcasts, Google Podcasts, Spotify, the ABC News app or wherever you get your podcasts.