A catastrophe is unfolding in the wake of Cyclone Idai, which hit the southern African countries of Mozambique, Zimbabwe, and Malawi on March 15.

In all, the storm is believed to have killed more than 750 people across the three countries, with the most deaths occurring in Mozambique, where the storm made landfall. More than 100,000 people are now living in shelters, and the coastal city of Beira, Mozambique, has been all but destroyed.

The storm brought intense, flooding rain and an estimated 13 feet of deadly storm surge to some coastal areas in Mozambique. The result of all that water: An “inland ocean” has formed near Beira. It’s a huge amount of water, measuring around 80 miles long by 15 miles wide.

The European Space Agency captured the extent of the flooding via satellite on March 19 (the flooded areas are in red). Floodwaters are beginning to recede, the Guardian reports, and as they do, we’re getting a clearer picture of the humanitarian crisis developing in the region.

In Mozambique, the United Nations Office for the Coordination of Humanitarian Affairs estimates that 446 people have died (the numbers are likely to continue to rise). Some 1,500 are injured, and 110,000 people are living in shelters.

Additionally, more than 58,660 homes have been destroyed by the storm. Beira, a city with a population of 400,000, continues to be mostly without power, and it’s still very difficult to bring supplies into the city via roads. “Fuel trucks are stuck ... on their way to Beira as the road is inaccessible,” the UN reports.

Zimbabwe and Malawi are also reeling from the storm. In Zimbabwe, the UN reports, 154 people are dead and 187 are still missing. An additional 121,000 people in the Chimanimani district of Zimbabwe (where the storm hit) are believed to need urgent food aid.

In Malawi, as of Friday, at least 56 people were reported dead and 82,700 people were displaced. “We are working round the clock to save the lives of those who survived and are facing incredible hardship,” the UN’s World Food Programme says.

More trouble may be coming. Where there’s flooding and poor sanitation, disease follows. The IFRC reports there are now cases of cholera — a bacterial infection that spreads when drinking water is tainted with feces — in Beira. “There are increasing reports of acute watery diarrhea in Beira, according to the Government,” the UN relays.

And “already, some cholera cases have been reported in Beira along with an increasing number of malaria infections among people trapped by the flooding,” the IFRC said in a statement.

As of Friday, there were also still people around Beira waiting on rooftops to be rescued. “They are alive, we are communicating with them, delivering food, but we need to rescue them and take them out,” Celso Ismael Correia, Mozambique’s minister of land, environment, and rural development, told reporters. “Our biggest fight is against the clock.” He says 15,000 people still need to be rescued.

You can help the victims of Cyclone Idai by donating to UNICEF, the International Medical Corps, Global Giving’s relief fund, Save the Children, the Red Cross, Catholic Relief Services, or Doctors Without Borders.

Over the past several days, photojournalists have been able to gain better access to the impacted areas. Here’s what the situation looks like.