BANGKOK - Bangkok residents jammed bus stations and highways on Wednesday to flee the flood-threatened Thai capital, while others built cement walls to protect their shops or homes from advancing waters surging from the country's flooded north.
"The amount of water is gigantic," Prime Minister Yingluck Shinawatra said. "Some water must spread into Bangkok areas but we will try to make it pass through as quickly as possible."
Some neighborhoods on the city's fringes were already experiencing waist-high flooding, but central areas remained dry. Everywhere, people were preparing for flooding that seemed all but inevitable.
Websites posted instructions on the proper way to stack sandbags. Many residents fortified vulnerable areas of their houses with bricks, gypsum board and plastic sheets. Walls of sandbags or cinderblocks covered the entrances of many buildings.
Concern that pumps would fail prompted a run on plastic containers in which to hoard water. Anticipating worse, one woman traveling on Bangkok's Skytrain system carried a bag of life vests.
Flood waterson Tuesday, halting commercial flights and underlining the gravity of the Southeast Asian nation's deepening crisis, which has seen waters inundate a third of the country and kill 366 people over the last three months.
Yingluck's government has declared a five-day public holiday for Thursday through Monday in affected areas, including Bangkok, while the Education Ministry ordered schools to close until Nov. 7. Many anxious city residents took advantage of the holiday to leave the capital or prepare for a possible watery siege.
Panic buying of food and other necessities emptied the shelves of many supermarkets. Bottled water and toilet paper were in especially short supply.
Yingluck urged everyone in the capital to move their belongings to higher ground and warned that the city could be swamped if flood barriers at three key locations fail.
"If the three spots ... remain intact, the situation will improve. However, if we can't protect one of the spots, then the surrounding areas will be flooded. In the worst case, if we can't protect all three spots, all of Bangkok will be flooded," she said.
A day earlier, she warned that the floods could range from 4 inches to 5 feet deep in the capital.
Thousands of people heeded advice to evacuate to official shelters, including many fleeing for a second or third time after their original refuges were overtaken by the flooding.
The exodus included hundreds of inmates from three prisons many on death row who were taken by bus from Bangkok's northern suburbs to facilities in other provinces.
Residents living near Mahasawat Canal in western Bangkok evacuated on Wednesday after a rapid overnight rise in water.
"I decided to leave because the water came in very fast," said Jong Sonthimen, a 57-year-old factory cleaner. A boat carried her and two plastic garbage bags with her belongings to a Buddhist temple, where pickup trucks waited to take residents to a safer area.
Last week, Yingluck ordered key floodgates opened in Bangkok to help drain runoff through urban canals to the sea, but there is great concern that rising tides in the Gulf of Thailand this weekend could slow critical outflows and flood the city.