Mozambique has declared three days of national mourning as it struggles to recover from what the World Meteorological Organization is calling the Southern Hemisphere’s worst tropical cyclone on record. Rescue workers in the flooded city of Beira struggled to reach survivors who clung to trees or pleaded for help from rooftops, after Cyclone Idai destroyed 90 percent of the city, home to a half-million people. The death toll from the storm rose to more than 200 in Mozambique and more than 100 in neighboring Zimbabwe Wednesday, with dozens more dead in Malawi, but those numbers are expected to rise. Flooding has disrupted the lives of millions across southern Africa, with the World Food Programme warning of a “major humanitarian emergency that is getting bigger by the hour.” This is WFP Emergencies Director Margot van der Velden.

Margot van der Velden: “We are confronted with severe flooding and cyclone effects; 600,000 people affected, possibly even going up to 1.7 and more million people affected by cyclone and flooding; communication completely broken; infrastructure severely damaged, particularly in the city of Beira, but also all the roads to Beira have been cut off.”

Cyclone Idai dropped more than two feet of rain in parts of southeastern Africa—nearly a year’s worth of rain in just a few days—an extreme weather event that climate scientists say is consistent with models of climate change.