At least 13 people are dead, roughly 40,000 homes have been damaged and 86,500 residents have sought federal assistance after a slow-moving storm poured as much as 31 inches of rain across southern Louisiana.

The flooding has overwhelmed neighborhoods around Baton Rouge and Lafayette, forced tens of thousands from their homes and produced one of the largest domestic disaster responses since Hurricane Sandy. Rivers rose beyond record levels, highways disappeared beneath muddy water and residents with fishing boats joined police, firefighters and the National Guard in rescuing neighbors.

President Obama issued a major-disaster declaration Sunday, making federal grants and loans available in designated parishes. The Federal Emergency Management Agency’s disaster record lists the incident period beginning August 11 and covers assistance for individuals, households and public recovery.

A nameless storm stalls over Louisiana

The disaster did not arrive as a hurricane with a familiar cone and countdown. A weak, nearly stationary low-pressure system drew unusually deep tropical moisture from the Gulf of Mexico and repeatedly sent intense rain over the same communities. The National Weather Service’s event summary reports widespread totals of 20 to 30 inches between August 11 and 13 across southeastern Louisiana and southwestern Mississippi.

Watson, northeast of Baton Rouge, recorded more than 31 inches. The Amite, Comite and other rivers surged to major or record flood stages, pushing water into communities well beyond mapped high-risk zones. In Livingston Parish, officials estimated that most homes suffered damage; in Ascension Parish, water invaded subdivisions that many residents believed were safely removed from river flooding.

The scale reflects not only the total rainfall but its concentration. An early meteorological assessment published during the event estimated that the unnamed system released about 7.1 trillion gallons of water over Louisiana, more than three times the rain Hurricane Katrina delivered to the state.

Rescues give way to a housing emergency

During the worst hours, emergency crews and volunteers pulled people from rooftops, vehicles and attics. The informal “Cajun Navy”—residents navigating flooded streets in privately owned boats—became a central part of the rescue network when official resources were stretched thin. Shelters housed thousands while authorities searched inundated areas and checked reports of missing residents.

As water recedes, the emergency is becoming one of housing, sanitation and basic services. Gov. John Bel Edwards said about 40,000 homes had been affected and thousands of families would be displaced for weeks or months. Reuters reported Thursday that approximately 86,500 people had already registered for federal aid, a number likely to keep rising as communications and roads reopen.

Many flooded households lack insurance because their properties were outside areas considered at highest risk. Federal grants can cover temporary housing and limited repairs, while Small Business Administration loans may finance larger losses, but neither mechanism guarantees that a family will be made whole. The mismatch between mapped risk and actual flooding will be one of the hardest recovery questions.

Federal aid expands across the region

FEMA has opened disaster-recovery centers and is sending inspectors to document damage. The federal declaration initially covered four parishes and has expanded as assessments arrive. The National Guard, Coast Guard and local agencies continue rescue and supply missions, while volunteer organizations distribute food, water, medicine and cleaning materials.

By Tuesday, the death toll had reached 11 and officials estimated that 40,000 homes were affected, according to contemporaneous Associated Press and ABC News reporting. Two more deaths were subsequently confirmed. The disaster has also closed schools, interrupted businesses and damaged public buildings, roads and utilities.

Homeland Security Secretary Jeh Johnson toured the region Thursday and said the federal government would remain engaged through recovery. Political attention intensified Friday when Republican presidential nominee Donald Trump and running mate Mike Pence visited damaged communities. Reports ahead of the visit noted that Edwards welcomed genuine assistance while cautioning against diverting police and rescue resources for a political event.

A recovery measured in months and years

The immediate work is straightforward but immense: shelter displaced families, restore utilities, remove debris, prevent mold and reopen roads. The longer task will require decisions about rebuilding standards, drainage, insurance and flood maps in places where an event of extraordinary rarity has exposed thousands of homes.

Louisiana’s experience also demonstrates the danger of storms without names. Residents accustomed to hurricane warnings had less time to recognize the scale of a system that lacked strong winds but carried exceptional moisture. The absence of a coastal landfall did not reduce the flood threat; it may have made the danger easier to underestimate.

The disaster’s full cost cannot yet be measured. Damage estimates made while many neighborhoods remain inaccessible will change, and the number of people seeking aid will rise. What is already clear is that rainfall statistics have become household losses on an enormous scale: cars submerged, schools closed, family photographs ruined and mortgages attached to houses that cannot be occupied.

For now, the response remains a combination of federal resources, state coordination and local improvisation. Boats that carried residents to safety are delivering supplies. Churches and civic buildings have become shelters. Families are returning to waterlogged homes to salvage what they can. The rain has ended, but Louisiana’s emergency has moved into a more difficult phase—one in which recovery depends on whether assistance can reach tens of thousands of households before temporary displacement becomes permanent.