Bangkok's residents are leaving the Thai capital in their thousands, after warnings that dikes holding back flood waters may not last much longer.
The prime minister says it's a fight against the forces of nature.
The government's called a five-day emergency holiday and is warning people to get out if they can.
SOUNDBITE: Pornchai Tangsuwongthai, Bangkok resident, saying (Thai):
"We're heading off to Hua Hin because people said it will be difficult, we should leave. We planned to stay for at least three more days. We'll monitor the situation. If it gets worse we won't come back."
At the city's main railway station, all services northwards, have been halted because of flooded tracks.
People are also crowding onto buses to escape.
Don Muang airport, used for domestic flights, has been shut since Tuesday.
Not everyone is going.
Some say they're not prepared to leave their homes and belongings, whatever the risk.
SOUNDBITE; Chetsada Baromasook, Bangkok resident, saying (Thai):
"We don't want to leave our village. We have families, we have children. There are other difficult circumstances. We don't want to move our belongings. We'll stay and fight, everyone will fight."
Thailand's worst floods in half a century have inundated large parts of north and central regions.
The disaster has claimed at least 373 lives.
The chaos caused by unusually heavy monsoon rain since mid-July has disrupted the lives of some two and a half million.
There's also likely to be a cost to the nation's tourism industry.
Britain has already warned against all but essential travel to Bangkok.
China is urging its citizens not to go there at all, and telling those in what it called the disaster zone to leave immediately.
Paul Chapman, Reuters
