Satellite images taken by NASA's Earth Observatory show the moments before and after the entire city of New Orleans lost power in Hurricane Ida.

The storm slammed into the Bayou State on Sunday as a Category Four hurricane with 150 mph winds and torrential downpours, toppling a major transmission tower and knocking out thousands of miles of power lines and hundreds of substations.

All of New Orleans was left without electricity in the aftermath, with officials relying on generators to power the local hospitals, as more than one million reported power outages.

On Thursday, some electricity returned to parts of the Big Easy, but more than 900,000 people in the state were still in the dark,  and do not know when their suffering will end.

The death toll in the storm-ravaged region rose to at least six after a coroner confirmed a 65-year-old woman had drowned in her Louisiana home. 

Even as the power was slowly coming back on before dawn on Thursday along Bourbon Street and other parts of New Orleans, the widespread loss of electricity could be seen from space.

A team of scientists from NASA's Goddard Space Flight Center and the Universities Space Research Association mapped the outages using satellite imagery from August 9, before the storm ravaged the area, and August 31, in its aftermath.