Thailand's prime minister said Bangkok was fighting the forces of nature yesterday as residents fled, rivers swelled and floodwater threatened to burst through dikes protecting the capital.
The country's worst flooding in half a century, caused in part by unusually heavy monsoon rain, has killed 373 people and disrupted the lives of nearly 2.5 million, until now mostly in the north and central provinces.
But Prime Minister Yingluck Shinawatra said the crisis had now reached a critical point for Bangkok.
"It seems like we're fighting against the forces of nature, massive floodwater that is causing damage to several of our dykes," she said.
"What we can do now is to manage it, so that it flows slowly, otherwise everybody will suffer."
As Ms Yingluck's voice trembled, reporters asked if she was crying.
"No. I haven't cried and I won't. I'll be strong to solve this problem for the Thai people.
"Right now we need to release floodwater to the sea as soon as possible and we need a quick rehabilitation plan," she said.
Traffic in central Bangkok was light on the first day of a five-day holiday, declared by Ms Yingluck's government so people could leave.
However, a main road out of the city to the flood-free south was jammed with an exodus of cars to the seaside town of Hua Hin and the eastern resort city of Pattaya, where hotel rooms and homes to rent were hard to find.
"We're heading off to Hua Hin because people said it'll be difficult, we should leave. If it gets worse, we won't come back," resident Pornchai Tangsuwongthai told Reuters TV.
Bangkok, a city of at least 12 million people that accounts for 41 percent of Thailand's GDP, is in danger from run-off water from the north coinciding with high tides on the Chao Phraya river, which is already at a record high level in places.
Bangkok governor Sukhumbhand Paribatra, who has warned many parts of the capital could be in danger by the weekend, said not all of the city would be hit.
"As the person in charge of Bangkok, I believe that the water will not flood every district. Some districts might not be inundated," he told reporters.
The defence ministry said 50,000 armed forces personnel were standing by with 1,000 boats and 1,000 vehicles to help evacuate people.
The government crisis centre said there would be evacuation facilities in eight provinces that could take in between 100,000 and 200,000 people.