Villahermosa, the state capital of Tabasco, is seen after the river Grijalva burst its banks Oct. 31, 2007. Thousands of homes were flooded on Wednesday after several rivers burst their banks in the southern Mexican state of Tabasco and heavy rains left 70 percent of the swampy region under water.(Xinhua/Reuters Photo)

       BEIJING, Nov. 2 -- In a state of Mexico famously known for its hot sauce, thousands of Tabasco residents were clinging to rooftops or huddled inside waterlogged homes Thursday in an attempt live through the worst flooding the low-lying Gulf state has witnessed in 50 years.

       Heavy rains for the last week have caused rivers to overflow, leaving at least 70 percent of the state -- and 80 percent of the capital -- under water. So far, one death was reported and nearly all services, including drinking water and public transportation, were shut down in Villahermosa.

       "The situation is extraordinarily grave: This is one of the worst natural disasters in the history of the country," President Felipe Calderon said in a televised address Thursday night.

       The rain had stopped Thursday, but weather forecasters predicted more in the coming days. The flooding was not related to Tropical Storm Noel, which pounded the Caribbean.

       The Grijalva River, one of two large waterways ringing Villahermosa, has risen 6.5 feet above its "critical" level and gushed into the city's center. Authorities said some of the rivers were continuing to rise.

       Rescue workers in boats and helicopters plucked desperate residents from their rooftops and led thousands to shelters, but the task was proving to be more than they could handle.

       Of the estimated 700,000 people whose homes were flooded, damaged or cut off, 300,000 still had not been rescued Thursday and potable water supplies were exhausted in Villahermosa, Tabasco Gov. Andres Granier said. Police, soldiers and military workers were still trying to reach them.

       The state of Chiapas, which borders Tabasco to the south, also reported serious flooding, with officials there estimating that more than 100,000 people had been affected.