It was a day many in New Orleans had planned to spend commemorating the terrible cost of Hurricane Katrina exactly 16 years ago.

Instead of those peaceful, sombre events they found themselves sitting in the dark as Hurricane Ida battered the Big Easy and knocked out power to the whole city.

The power of Ida was astonishing even for a city that has become pretty used to hurricanes arriving on its doorstep. This is the fourth to make landfall here in a year.

Hurricane Ida makes landfall – follow live updates

The emergency services announced conditions were too bad for them to respond to calls for help. Rescue crews said they would not be able to begin operations to reach people for hours.

It meant those who chose to stay and ride out Ida were on their own.

The authorities believe – they hope – that the vast majority of people in the most vulnerable areas did choose to evacuate in recent days. Some estimates suggest 98% did.

But they fear there will have been loss of life among those who didn’t.

Ida packed a long, lingering punch over the Gulf Coast and it isn’t finished yet. These hurricanes are becoming wetter and more intense, scientists say, as the result of climate change, with warmer seas and more water vapour in the air.

Katrina took the lives of 1,800 people in 2005, the result of a series of catastrophic failures amidst the storm.

Ida might not have a cost on the same scale but it is another reminder for the city of what it’s future might look like.

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