Hurricane Sally has hit with a vengeance, pummelling the southern US with torrential rain, causing widespread flooding and ferocious 168km/h winds which tore through buildings.
The newly strengthened hurricane pounded the Florida Panhandle and southern Alabama when it finally made landfall, moving steadily across the coast with deadly force.
At Gulf Shores, Alabama on the tip of Mobile's port east of New Orleans, the winds blew out the sides off a condominium and ripped off roofs.
The National Hurricane Center warned of "catastrophic" and "life-threatening" flooding along parts of the north-central Gulf Coast, with rainfall predicted to last up for up to two days.
Moving north to northeast, Category 2 Hurricane Sally has the potential to increase its wind speed with damaging gusts.
It is moving at a painfully slow 3-5km/h, pelting the coast with heavy downpours and winds which played havoc with power supply, making for a "nightmare" scenario.
By early Wednesday, 150,000 homes or businesses experienced outages in Mobile, Alabama.
Gulf Shores instituted a curfew because floods and dangerous debris were considered life-threatening.
A state of emergency has been declared in Alabama, Florida and Mississippi, with the National Hurricane Centre saying the slow pace of the storm was only going to "exacerbate flooding" in impacted areas.
National Weather Service forecaster David Eversole said the way the hurricane is moving is a serious concern.
"It's not common that you start measuring rainfall in feet," he said.
"Sally's moving so slowly, so it just keeps pounding and pounding and pounding the area with tropical rain and just powerful winds.
"It's just a nightmare."
Bridges have been washed away and parts of highways were closed due to flooding and winds, with people being advised to stay home and keep off the roads.
Photos and videos from impacted areas show streets turned into rivers, with cars almost completely covered in floodwater.
In Escambia County, Florida, where the city of Pensacola is located, more than 80 per cent of buildings had lost power.
County Sheriff David Morgan said crews in boats and high water vehicles were rescuing thousands of people from their homes and elsewhere due to heavy flooding.
In Walton County, Florida, the sheriff's office tweeted "NO ONE should be on the roads right now in Walton County.
"Conditions during #HurricaneSally are very dangerous and there is widespread flooding on roadways. Please stay inside unless there is an emergency."
A storm chaser in Gulf Shores filmed a high-rise building with the sides torn off, leaving bedrooms open to the elements.
The National Hurricane Centre described Hurricane Sally as a rare storm that could make history, like Hurricane Katrina in 2005 which caused $125 billion worth of damage in New Orleans.
"Sally has a characteristic that isn't often seen and that's a slow forward speed and that's going to exacerbate the flooding," the Centre's Ed Rappaport told Associated Press.
He compared Sally's slow path of destruction with Houston's Hurricane Harvey in 2017, which is one of the US's costliest hurricanes in history.
He predicted that a record-breaking 76cm of rain could fall in some areas.
The National Hurricane Centre reported than apart from Sally, three more hurricanes were lurking offshore in the Atlantic, Teddy, Vicky and Paulette.
Trouble may be coming early next week from Teddy, for the island territory of Bermuda which lies in the predicted path of this powerful hurricane, currently moving at 20km/h and at a strength of 160km/h.
Currently located south east of the Dominican Republic, Teddy is expected to strengthen in the next few days to become a major hurricane and reach a Category 4 in strength.