Clambering aboard rafts and trucks, residents on the outskirts of Bangkok fled their homes as flood waters inched closer to the heart of the Thai capital, while foreign governments urged their citizens to avoid all but essential travel.
The start of a government-declared five-day holiday fuelled an exodus of thousands of people fearing the worst. They queued at bus stations and took to clogged highways and airports to get out of town.
Tears welling, Prime Minister Yingluck Shinawatra acknowledged that her government could not control the approaching deluge.
"What we're doing today is resisting the force of nature."
The water bearing down on Bangkok was so massive that "we cannot resist all of it", she added.
The floods, the heaviest in Thailand in more than half a century, have drenched a third of the country's provinces and killed nearly 400 people. For weeks, they have been flowing south toward the Gulf of Thailand.
By yesterday, flooding had inundated seven of Bangkok's 50 districts, most on the northern outskirts, turning roads into rivers and swamping homes and offices.