London (CNN) -- After a wild and stormy night that claimed two lives, many communities in southern England face a high risk of flooding Saturday from still-rising rivers.
Severe flood warnings are in place along the Thames Valley to the west of London, as well as in southwest and central England.
The Environment Agency warned that flood risk will continue for at least another week.
An elderly passenger died Friday aboard the British-based cruise ship MS Marco Polo after it was hit by a "freak wave during adverse sea conditions," according to the ship's owner, Cruise & Maritime Voyages.
The rogue wave struck as the ship made its way into the English Channel en route from the Azores to its home port in Tilbury, southeast England, it said.
As high winds whipped southern England on Friday night, a 49-year-old woman was killed when the front of a building collapsed onto her vehicle in central London, police said. Two other passengers in the car were injured. Police said the collapse happened during bad weather, but they were unable to say if it was directly related.
On Saturday, amid increasing questions about the government response, Prime Minister David Cameron visited Chertsey, Surrey and thanked the military for its help during the crisis.
The Environment Agency reported that 16 severe flood warnings remained in place Saturday, meaning there is a danger to life, as well as 151 lower-level flood warnings in different parts of the country.
Thames Barrier, which is deployed to prevent the tidal river now flooding central London with devastating consequences, was shut for a record 16th consecutive time to help reduce flood risk along the Thames, according to the Environment Agency.
The emergency will continue over the coming days for the Somerset Levels and Moors, where river levels continue to rise, posing a further threat to those already affected by recent flooding, the agency said.
"Despite an improving forecast the risk of flooding will continue for many communities in southern parts of England over the next few days," Paul Leinster, the Environment Agency's chief executive, said in a statement.
More rain is forecast over the weekend, pushing river levels ever higher.
After the wettest January in England in 2½ centuries, February has so far brought little relief.
The River Thames has reached its highest levels for over 60 years in some places, bringing flood misery to thousands of people living in the Thames Valley.
The towns of Maidenhead and Windsor, where the queen has a castle, and communities in the counties of Surrey, Buckinghamshire, Berkshire and Reading are all at risk from the Thames.
Residents desperate to hold back the rising waters have sandbagged entrances to their homes and businesses.
Princes William and Harry lent their help to the flood defense effort Friday morning, as they joined soldiers who hefted sandbags in the village of Datchet in Berkshire.
There is also a risk of flooding on the River Severn in Gloucester and on the Somerset Levels, in southwest England. Some communities on the Somerset Levels have been inundated for weeks.
As well as high river levels, saturated ground from weeks of heavy rain mean that there is nowhere for water to go.
Severe gales, large waves and high sea levels were expected to bring a high risk of coastal flooding to parts of the Dorset coast on Saturday, the Environment Agency said.
Other areas along the south coast of England will also be battered by extreme weather.
Nearly 6,000 properties have been flooded since the beginning of December, more than 1,000 of them in the wealthy areas in the Thames Valley. Leinster said more than 1.3 million properties have been protected since the start of December through the Environment Agency and use of the Thames Barrier.
CNN's Erin McLaughlin, Talia Kayali, Chelsea J. Carter, Brian Walker, Ray Sanchez and Bharati Naik contributed to this report.