October 27, 2011 -- Updated 1901 GMT (0301 HKT)
Bangkok residents used the holiday to stream out of the capital, seeking higher ground or temporary shelters. Many saw floodwater enter their homes uninvited, their belongings soaked beyond salvage.
Most of Bangkok was expected to be flooded Thursday, with up to 1 meter (3.2 feet) of water in some areas, said Thai Prime Minister Yingluck Shinawatra, as the Chao Phraya River threatened to spill over holding walls and into the city of 12 million people.
Several districts were under a mandatory evacuation order.
Yingluck conceded Bangkok is entering a critical stage, the MCOT news agency reported. She said it was impossible to divert the floodwater and that it would certainly flow through every part of the metropolitan area.
"There is water from underground coming up," said Pracha Promnok, chief of the Flood Relief Operations Center. "We are unable to do anything (to stop it)."
Yingluck fielded criticism that the flood relief center had not done enough and called on the public -- with tears in her eyes -- to sympathize with emergency staff, as some of them had also become victims of the flooding.
"Many are exhausted and some problems cannot be controlled and were not caused by (the center)," Yingluck said, according to MCOT.
Thailand's government declared public holidays through the rest of the month in 21 flood-affected provinces, and appealed to Bangkok residents to head to the countryside.
People flocked to bus terminals and crowed the Suvarnabhumi Airport, the main airport, desperate to flee to safer places. The smaller domestic airport was closed with water on the runways but Suvarnabhumi was operating normally, protected by 3.5 meters (almost 12 feet) of dikes, said Toopetch Booyarith of the Airport Authority of Thailand.
"We are confident that we will not be affected," Toopetch said.
A normally bustling metropolis notorious for traffic snarls stood empty Thursday, save a few public buses and taxis still able to move along some streets. There was even water standing before the Grand Palace, perhaps the most-adored of Bangkok's landmarks.
Hotels offered budget prices to accommodate the flood-affected and some tourist areas reported full occupancies. In the resort town of Pattaya, fleeing Bangkok residents found it hard to get a room in hotels overflowing with European tourists, the Bangkok Post reported.
U.S. Ambassador Kristie Kenny said the crisis was slow-moving and it was hard to know what would be hit next.
The United States has already provided civilian relief resources including water pumps, purifiers and life vests, she said, and two U.S. helicopters are helping the Thai military survey the extent of the flooding.
The Thai floods, caused by heavy monsoonal rains that saturated rivers, have killed 373 people nationwide and affected more than 9.5 million people, authorities said.
The government has called the flooding the worst to afflict the nation in half a century and said it might take more than a month before the waters recede in some areas.
The government has set up more than 1,700 shelters nationwide, and more than 113,000 people have taken refuge.
Overall damage from the floods has risen and could top $6 billion, with the worst yet to come as the waters destroy shops and paralyze factories nationwide, the Thai Finance Ministry said.
