SEATTLE, NOV. 26 -- Flood water receded today, but hundreds of people stayed away from homes they abandoned over the weekend after heavy rains caused the second ruinous floods in two weeks.

One man was presumed dead, and a pontoon bridge linking Seattle and its eastern suburbs sank. Many residents had just managed to return home and start cleaning up earlier damage when the new rainstorms hit.

At least 2,600 people were evacuated as 20 rain-swelled rivers spilled over their banks, authorities said. Most of the flooding occurred west of the Cascade Mountains, which form the north-south spine of the state, inundating much of western Washington. Rural areas were hit hardest.

More rain but in less quantity was forecast for tonight and Tuesday.

"Except for the Chehalis River, the worst is over," said Dick Milne, spokesman for the state Division of Emergency Management. A flood surge was moving down that river toward Grays Harbor on the coast, and officials said more evacuations downstream might be necessary.

High-water marks were set on at least six rivers. State officials, who tallied more than $40 million in flood damage earlier this month, said that figure would soar.

A storm that dumped a record 3 1/2 inches of rain on Seattle in two days was blamed for collapse of the old Lake Washington floating bridge, which was being renovated to carry the new eastbound lanes of Interstate 90.

About 2,100 feet of the four-lane, 8,600-foot bridge sank in 200 feet of water Sunday morning. Bridge debris severed cables anchoring the new, seven-lane I-90 bridge, 60 feet north of the old structure.

State engineers closed the year-old bridge and said it would be reopened only after temporary replacement cables are installed.

The bridge is a chief artery linking Seattle to populous suburbs to the east, handling 110,000 vehicles daily. Commuters accustomed to a 12-mile drive between Bellevue and Seattle were forced to endure a clogged, 30-mile detour today.

King County police said Scot Alan Scott, 28, of Duvall, was missing and presumed drowned Sunday after he drove past a barricade on a county road, left his stalled car and tried to walk through high water. He was swept into the Snoqualmie River. His wife and 6-month-old son were rescued.