Venezuela's military launched a dramatic rescue operation today, airlifting thousands of people from storm-ravaged coastal areas while President Hugo Chavez commanded paratroopers who rappelled from helicopters to deliver supplies to those waiting to be plucked to safety.

Authorities said three dozen helicopters had rescued more than 15,000 people--many of them stranded on rooftops--in Vargas state, north of the capital, that has suffered the worst destruction from deadly flooding and mud slides caused by rains that have drenched the country for four days.

In the stepped-up recovery effort involving 12,000 troops, at least one battleship and several amphibious vehicles have picked up more than 3,000 people on the shores of badly battered towns along Venezuela's Caribbean coast.

Chavez said on television late tonight that more than 500 people had died in the worst natural disaster to hit Venezuela in 50 years and that 6,000 people were missing. The death toll was expected to rise. Morgues have reported receiving large numbers of bodies, suggesting that most of those unaccounted for are dead. It's also estimated that 150,000 people have been left homeless since the downpours began Wednesday.

Those rescued today were taken to crowded shelters and hospitals, where some were greeted by tearful relatives. At Caracas's main receiving shelter in a sports arena at United Nations Park, hundreds of homeless families slept and milled about in stifling heat amid a sea of donated mattresses.

At Venezuela's main international airport outside Caracas, which remains closed to commercial flights and has become a frenzied refugee center, Eduardo Castillo, 32, said as he stumbled off a rescue helicopter from the coastal town of Carmen de Uria, "Thank God for life. But I am so sad that the town I was born in has been wasted to nothing."

Thousands of others remained trapped in their apartments in high-rise buildings ringed by muddy flood waters that, in some cases, rose up to three stories. Electricity and telephone service were knocked out in large sections of the country while drinkable water remained in short supply. Fears mounted that disease would start to spread.

Chavez, a former paratrooper, personally oversaw an elite squad of about 1,500 men who were dropped on remote beaches and fields and slid down ropes from helicopters in more rugged areas.

"In a first phase, the paratroops will provide food and water rations. In a second phase, loads of combat rations and communications supplies will be dropped so people can communicate with pilots with signals from roofs to ask for more help," Chavez, wearing camouflage fatigues and a red paratrooper's beret, told reporters.

Chavez said the destruction across Venezuela would provide an opportunity to implement a plan contained in a new constitution approved by voters on Wednesday to relocate segments of the population to sparsely populated areas. "We have plans to create great cities in the south and the interior," he said. "We announced this plan months ago, but, unfortunately, nature has obliged us to accelerate it dramatically."

The United States has given $25,000 to the Venezuelan Red Cross and allocated another $200,000 for other relief. Three U.S. military helicopters have been delivered and six more are coming.

As the rains lightened throughout parts of the country today, the extent of the damage and human suffering became more apparent.

Veraza Brigida frantically paced near a small river that swelled into a raging torrent three days ago and swept away her 11-year-old son before it devoured their hovel in an impoverished Caracas neighborhood.

"The current just sucked him down as he was rushing home," said Brigida, clasping a photograph of the boy, sobbed. "God has to help me with my pain. I cannot bear this on my own. Oh God, take care of my son."