As New Orleans slips into lawlessness after Hurricane Katrina struck the Gulf of Mexico coast, officials say they can still only guess at the death toll of the disaster—though it is likely to be in the thousands. Many survivors are still waiting for help

THE natural catastrophe is past, but the human catastrophe in the wake of Hurricane Katrina seems to be worsening still. Around four-fifths of New Orleans was still under water on Thursday September 1st, three days after the storm slammed into Louisiana, with winds roaring up to 140mph. Much of the city is below sea level and its ageing levees—a system of flood walls, earthworks and pumping stations designed to hold the waters back—could not resist Katrina's might.

As the hurricane travelled on across Mississippi, Tennessee and Alabama, it left a trail of death and devastation there too. Officials say it is impossible to know how many people have been killed, but the official count has already moved into the hundreds; at least 30 died in a single catastrophic collapse of a seaside apartment building in Biloxi, Mississippi. In New Orleans, reports of bodies floating in the floodwaters herald a dreadful accounting to come; the mayor has said that the final death toll may be in the thousands. With many roads blocked by the floods and fallen trees, rescue workers and volunteers are working round the clock to reach the uncounted number in need of food, medical attention and uncontaminated drinking water.

But while catastrophes often bring out the best in people, in this case it has brought out some of the worst, too. Looters and armed gangs stalk New Orleans, fires started by arsonists rage as desperate refugees clamour for rescue, and CNN has reported shots fired at medical convoys evacuating the sick and helpless. On Thursday, more troops were sent in to quell the lawlessness. In the early hours of Friday, the waterfront area was rocked by a series of massive blasts that sent clouds of acrid smoke drifting across the city. It was not clear what had caused the explosions, which, according to early reports, may have come from a chemical plant.

Some are warning that it could be a matter of weeks, or even months, before electricity is restored to all of the millions who lost it in the wake of the storm. The army's chief engineer says it could take up to 30 days to remove the water, and New Orleans officials have said it could be several months before those who fled before Katrina hit are able to return.

Though most of the city's residents left before the storm, huge efforts are now being made to rescue and evacuate those who remained behind to care for pets or ageing relatives and neighbours, or simply because they had nowhere else to go. The Superdome, a downtown sports arena, was a temporary home for at least 20,000, but heat, humidity, failed plumbing and a lack of supplies have turned it into a festering nightmare. Buses are now being brought in to transport the refugees to a stadium in Houston, but violence and the overwhelming number of the needy have slowed this and other evacuation efforts. Reports have emerged of people dying in the crowds waiting for buses to take them to safety.

More worrisome still is the toll of disease on those who are trying to wade to safety. The floodwaters are now a toxic stew of raw sewage, household and industrial chemicals, and the rotting corpses of the people and pets who drowned as the waters rose. Doctors worry that this may mean an increase in the sorts of gastrointestinal diseases commonly seen only in the poorest countries. The water is also an excellent breeding ground for mosquitoes, particularly in the warm, wet climate of the Gulf Coast, which could mean a spike in mosquito-borne illnesses such as West Nile virus.

Once the floodwaters have been pumped out of the city—which may take weeks—insurers expect a deluge of claims. Estimates of the losses range from $9 billion to $25 billion. The high end of this range would make Katrina the most expensive natural disaster in America's history for underwriters, topping the $21 billion paid out after Hurricane Andrew in 1992.

To the insurers' losses must be added the cost to the government of rescue operations, plus many uninsured losses that will ultimately be met by private individuals or the taxpayers. For instance, homeowners' insurance typically does not include flood coverage, which is underwritten by the federal government, and business-interruption insurance may not cover losses from looting. There will undoubtedly be wrangling between insurance adjusters, homeowners and the feds over what water damage was due to the storm, and what is attributable to the rising flood.