Authorities said residents had until dusk to retrieve scattered mementos and assess what might remain of homes and businesses.
Meanwhile, search and rescue crews continued to comb through the rubble as state Army National Guard troops and heavy equipment were rushed into the remains of the south-central Kansas farming community, which had a population of about 1,600.
By early today the tornado's death toll remained at eight in Greensburg and one in neighboring Pratt County. At least 50 people were injured and several remained hospitalized in critical condition, authorities said.
''It's been one of the most destructive tornadoes in the last 10 years,'' said National Weather Service meteorologist Matt Gerard.
The twister struck in an area of the central United States known as tornado alley, which encompasses parts of a half-dozen states and is prone to the destructive funnel clouds that kill an average of 70 Americans each year.
Kansas Emergency Management spokeswoman Sharon Watson said searchers and dogs had gone over the town twice but the depth of the debris field and the fact that some people remain unaccounted for made it necessary to continue efforts.
Watson said the state was rushing to hire contractors to help clear the tons of debris. Much of the equipment that the state would normally use -- Humvees, frontloaders and dump trucks controlled by the state's Army National Guard -- has been sent to the war in Iraq.
Still, nearly 70 Kansas Army National Guard troops were arriving in Greensburg on Monday to supplement about 40 troops already on the ground and some state-owned Humvees were available for use in clearing wreckage, Watson said.
Federal Emergency Management Agency director R David Paulison was scheduled to tour the area today and FEMA said it was working to set up trailers and other assistance for displaced residents.
The National Weather Service said the twister's winds were estimated to have reached 205 mph, making it an F5, the highest category on its scale. It hit Greensburg at about 2145 hrs (local) on Friday and stayed on the ground about an hour, traveling about 22 miles and wreaking a path of destruction 1-3/4 mile wide.
REUTERS RS HS2226