Neighbourhoods in the capital city of Villahermosa in the state of Tabasco are under water as the situation becomes critical. Mexican President Felipe Calderon addressed the nation calling this one of the worst disasters in the country's history. An aerial view shows how floodwaters turned many towns and swaths of the state capital, Villahermosa, into murky lakes. as heavy rains flooded nearly the entire southern state of Tabasco. Tens of thousands of Mexicans were trapped on rooftops and others clung to lampposts. Many of the state's regular shelters were evacuated after floodwaters overtook them. Some 20 men and women seen here were rescued by a helicopter manned by the federal police when the secondary school turned shelter where they were staying, became flooded up to the roof - about four metres. The Villahermosa neighbourhood of Las Gaviotas Sur, is located five kilometres from River Grijalba. At least 500,000 people were made homeless and one person was killed in the worst flooding the swampy state has seen in more than 50 years. Tabasco Gov. Andres Granier said more than 1 million people -- about half of the state's population -- were "in the water," and scores of people called local radio programs pleading to be rescued. Rescue workers steered boats and skiffs up and down streets, fishing thousands from the brown waters and dropping them off in dance halls, parking garages and other improvised shelters. Around 269 refuges are sheltering nearly 30,000 people. Some 670 neighbourhoods in 17 municipalities in the state have been flooded. Agustina Rodriguez who was found on the roof of her home said that she never expected the situation to become so serious. "Horrible, we didn't eat, we had nothing, without clothes, we didn't rescue anything, we lost everything. We were on the roof of our house in the open air, without a roof over our head. We never thought this would be so big," Granier said thousands of soldiers and volunteers were working to strengthen a raised four-lane highway that serves as a levy around the capital. If it breaks, he said, 95 percent of the city would be under 7 feet (2 meters) of water. Officials have said Tabasco lost all of its banana and other crops, and that four-fifths of the state was under water. The floods were triggered by storms that have wreaked havoc in the oil industry along Mexico's Gulf coast. In an address to the nation, Mexican President Felipe Calderon, asked for the country's support and solidarity of all Mexicans, calling this the worst natural disaster in the country's history. "As you know, the torrential rains from the past days have caused flooding in most of the state and have left thousands homeless. Many people from Tabasco have lost their homes, belongings and plantations to support their families. Others are still at home, but without access to food, water or medicines. The situation is extraordinarily serious," he said. "It's one of the worst natural disasters in the history of the country. At this moment I ask the people of Tabasco to remain calm. This is very important. Don't lose hope. Organize yourselves with the neighbours and coordinate with authorities. We are working to help them at these difficult moments to out full capacity," Calderon said. He asked the general population to help in any way possible with financial and supplies support. Calderon visited Tabasco on Wednesday (October 31) to tour affected areas and asses damage and he plans to return on Friday (November 02).