Weeklong heavy rains caused rivers in southern Mexico to overflow, flooding at least 70% of the state of Tabasco and affecting the homes of at least 900,000 people, as well as dozens of medical facilities.

Floodwaters also submerged about 80% of Villahermosa, the state’s capital.

Using military trucks (bearing water, food and clothing), helicopters and boats, police, soldiers and rescue workers raced to rescue an estimated 300,000 flood victims stranded on rooftops and trees.

Officials turned parking garages and other structure into makeshift shelters.

At least one death was reported.

Calling the state “devastated,” Tabasco Governor Andres Granier told reporters, “We have lost 100% of our crops and 70% of the state is under water.” Comparing the current emergency with the damage caused by Hurricane Katrina, he said, “New Orleans was small compared to this.”

Health officials warned of the increasing scarcity of food and clean drinking water, and the possibility of waterborne disease epidemics, such as cholera.

“The situation is extraordinarily grave,” said Mexican President Felipe Calderon in a televised address. “This is one of the worst natural disasters in the history of the country.”

Elsewhere, the state of Chiapas has also suffered serious flooding, affecting more than 100,000 residents, authorities estimated.